diff --git a/src/Form/AdminPages/BaseEntityAdminForm.php b/src/Form/AdminPages/BaseEntityAdminForm.php
index 005c6a0c..f92c21e2 100644
--- a/src/Form/AdminPages/BaseEntityAdminForm.php
+++ b/src/Form/AdminPages/BaseEntityAdminForm.php
@@ -34,6 +34,7 @@ namespace App\Form\AdminPages;
 
 use App\Entity\Base\NamedDBElement;
 use App\Entity\Base\StructuralDBElement;
+use App\Form\Type\StructuralEntityType;
 use FOS\CKEditorBundle\Form\Type\CKEditorType;
 use Symfony\Bridge\Doctrine\Form\Type\EntityType;
 use Symfony\Component\DependencyInjection\ParameterBag\ContainerBagInterface;
@@ -70,8 +71,8 @@ class BaseEntityAdminForm extends AbstractType
                 'attr' => ['placeholder' => 'part.name.placeholder'],
                 'disabled' => !$this->security->isGranted($is_new ? 'create' : 'edit', $entity), ])
 
-            ->add('parent', EntityType::class, ['class' => get_class($entity), 'choice_label' => 'full_path',
-                'attr' => ['class' => 'selectpicker', 'data-live-search' => true], 'required' => false, 'label' => 'parent.label',
+            ->add('parent', StructuralEntityType::class, ['class' => get_class($entity),
+                 'required' => false, 'label' => 'parent.label',
                 'disabled' => !$this->security->isGranted($is_new ? 'create' : 'move', $entity), ])
 
             ->add('not_selectable', CheckboxType::class, ['required' => false,
diff --git a/src/Form/PartType.php b/src/Form/PartType.php
index 597ed97c..08ed5324 100644
--- a/src/Form/PartType.php
+++ b/src/Form/PartType.php
@@ -33,6 +33,7 @@ use App\Entity\Parts\Category;
 use App\Entity\Parts\Manufacturer;
 use App\Entity\Parts\Part;
 use App\Entity\Parts\Storelocation;
+use App\Form\Type\StructuralEntityType;
 use FOS\CKEditorBundle\Form\Type\CKEditorType;
 use Symfony\Bridge\Doctrine\Form\Type\EntityType;
 use Symfony\Component\Form\AbstractType;
@@ -65,20 +66,20 @@ class PartType extends AbstractType
             ->add('description', TextType::class, ['required' => false, 'empty_data' => '',
                 'label' => 'description.label', 'help' => 'bbcode.hint', 'attr' => ['placeholder' => 'part.description.placeholder'],
                 'disabled' => !$this->security->isGranted('description.edit', $part), 'empty_data' => '' ])
-            ->add('instock', IntegerType::class,
+            /*->add('instock', IntegerType::class,
                 ['attr' => ['min' => 0, 'placeholder' => 'part.instock.placeholder'], 'label' => 'instock.label',
-                'disabled' => !$this->security->isGranted('instock.edit', $part), ])
+                'disabled' => !$this->security->isGranted('instock.edit', $part), ]) */
             ->add('mininstock', IntegerType::class,
                 ['attr' => ['min' => 0, 'placeholder' => 'part.mininstock.placeholder'], 'label' => 'mininstock.label',
                     'disabled' => !$this->security->isGranted('mininstock.edit', $part), ])
-            ->add('category', EntityType::class, ['class' => Category::class, 'choice_label' => 'full_path',
-                'attr' => ['class' => 'selectpicker', 'data-live-search' => true], 'label' => 'category.label',
+            ->add('category', StructuralEntityType::class, ['class' => Category::class,
+                'label' => 'category.label', 'disable_not_selectable' => true,
                 'disabled' => !$this->security->isGranted('move', $part), ])
-            ->add('storelocation', EntityType::class, ['class' => Storelocation::class, 'choice_label' => 'full_path',
+            /*->add('storelocation', EntityType::class, ['class' => Storelocation::class, 'choice_label' => 'full_path',
                 'attr' => ['class' => 'selectpicker', 'data-live-search' => true], 'required' => false, 'label' => 'storelocation.label',
-                'disabled' => !$this->security->isGranted('storelocation.edit', $part), ])
-            ->add('manufacturer', EntityType::class, ['class' => Manufacturer::class, 'choice_label' => 'full_path',
-                'attr' => ['class' => 'selectpicker', 'data-live-search' => true], 'required' => false, 'label' => 'manufacturer.label',
+                'disabled' => !$this->security->isGranted('storelocation.edit', $part), ]) */
+            ->add('manufacturer', StructuralEntityType::class, ['class' => Manufacturer::class,
+                 'required' => false, 'label' => 'manufacturer.label', 'disable_not_selectable' => true,
                 'disabled' => !$this->security->isGranted('manufacturer.edit', $part), ])
             ->add('manufacturer_product_url', UrlType::class, ['required' => false, 'empty_data' => '',
                 'label' => 'manufacturer_url.label',
diff --git a/src/Form/Type/StructuralEntityType.php b/src/Form/Type/StructuralEntityType.php
new file mode 100644
index 00000000..a91d8170
--- /dev/null
+++ b/src/Form/Type/StructuralEntityType.php
@@ -0,0 +1,145 @@
+<?php
+/**
+ *
+ * part-db version 0.1
+ * Copyright (C) 2005 Christoph Lechner
+ * http://www.cl-projects.de/
+ *
+ * part-db version 0.2+
+ * Copyright (C) 2009 K. Jacobs and others (see authors.php)
+ * http://code.google.com/p/part-db/
+ *
+ * Part-DB Version 0.4+
+ * Copyright (C) 2016 - 2019 Jan Böhmer
+ * https://github.com/jbtronics
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ *
+ */
+
+namespace App\Form\Type;
+
+
+use App\Entity\Base\StructuralDBElement;
+use App\Entity\Parts\Storelocation;
+use App\Repository\StructuralDBElementRepository;
+use Doctrine\ORM\EntityManagerInterface;
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\ChoiceList\Loader\CallbackChoiceLoader;
+use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
+use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\Form\FormInterface;
+use Symfony\Component\Form\FormView;
+use Symfony\Component\OptionsResolver\Options;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+/**
+ * This class provides a choice form type similar to EntityType, with the difference, that the tree structure
+ * of the StructuralDBElementRepository will be shown to user
+ * @package App\Form\Type
+ */
+class StructuralEntityType extends AbstractType
+{
+    protected $em;
+    protected $options;
+
+    public function __construct(EntityManagerInterface $em)
+    {
+        $this->em = $em;
+    }
+
+    public function configureOptions(OptionsResolver $resolver)
+    {
+        $resolver->setRequired(['class']);
+
+        $resolver->setDefaults(['attr' => ['class' => 'selectpicker', 'data-live-search' => true],
+            'show_fullpath_in_subtext' => true, //When this is enabled, the full path will be shown in subtext
+            'subentities_of' => null,   //Only show entities with the given parent class
+            'disable_not_selectable' => false,  //Disable entries with not selectable property
+            'choice_loader' => function (Options $options) {
+                return new CallbackChoiceLoader(function () use ($options) {
+                    return $this->getEntries($options);
+                });
+            }, 'choice_label' => function ($choice, $key, $value) {
+                return $this->generateChoiceLabels($choice, $key, $value);
+            }, 'choice_attr' => function ($choice, $key, $value) {
+                return $this->generateChoiceAttr($choice, $key, $value);
+            }
+        ]);
+    }
+
+    protected function generateChoiceAttr(StructuralDBElement $choice, $key, $value) : array
+    {
+        $tmp = array();
+
+        if ($this->options['show_fullpath_in_subtext'] && $choice->getParent() != null) {
+            $tmp += ['data-subtext' => $choice->getParent()->getFullPath()];
+        }
+
+        //Disable attribute if the choice is marked as not selectable
+        if ($this->options['disable_not_selectable'] && $choice->isNotSelectable()) {
+            $tmp += ['disabled' => 'disabled'];
+        }
+        return $tmp;
+    }
+
+    protected function generateChoiceLabels(StructuralDBElement $choice, $key, $value) : string
+    {
+        /** @var StructuralDBElement|null $parent */
+        $parent = $this->options['subentities_of'];
+
+        /*** @var StructuralDBElement $choice */
+        $level = $choice->getLevel();
+        //If our base entity is not the root level, we need to change the level, to get zero position
+        if ($this->options['subentities_of'] !== null) {
+            $level -= $parent->getLevel() - 1;
+        }
+
+
+        $tmp = str_repeat('&nbsp;&nbsp;&nbsp;', $choice->getLevel()); //Use 3 spaces for intendation
+        $tmp .=  htmlspecialchars($choice->getName($parent));
+        return $tmp;
+    }
+
+    /**
+     * Gets the entries from database and return an array of them
+     * @param Options $options
+     * @return array
+     */
+    public function getEntries(Options $options) : array
+    {
+        $this->options = $options;
+
+        /** @var StructuralDBElementRepository $repo */
+        $repo = $this->em->getRepository($options['class']);
+        $choices = $repo->toNodesList(null);
+        return $choices;
+    }
+
+
+    public function buildView(FormView $view, FormInterface $form, array $options)
+    {
+        //Allow HTML in labels. You must override the 'choice_widget_options' block, so that can work
+        //See extendedBootstrap4_layout.html.twig for that...
+        $view->vars['use_html_in_labels'] = true;
+
+        parent::buildView($view, $form, $options); // TODO: Change the autogenerated stub
+    }
+
+    public function getParent()
+    {
+        return ChoiceType::class;
+    }
+}
\ No newline at end of file
diff --git a/src/Form/UserAdminForm.php b/src/Form/UserAdminForm.php
index 089dc54c..c516a802 100644
--- a/src/Form/UserAdminForm.php
+++ b/src/Form/UserAdminForm.php
@@ -35,6 +35,7 @@ namespace App\Form;
 use App\Entity\UserSystem\Group;
 use App\Entity\Base\NamedDBElement;
 use App\Entity\Base\StructuralDBElement;
+use App\Form\Type\StructuralEntityType;
 use FOS\CKEditorBundle\Form\Type\CKEditorType;
 use Symfony\Bridge\Doctrine\Form\Type\EntityType;
 use Symfony\Component\Form\AbstractType;
@@ -66,8 +67,8 @@ class UserAdminForm extends AbstractType
                 'attr' => ['placeholder' => 'user.username.placeholder'],
                 'disabled' => !$this->security->isGranted('edit_username', $entity), ])
 
-            ->add('group', EntityType::class, ['class' => Group::class, 'choice_label' => 'name',
-                'attr' => ['class' => 'selectpicker', 'data-live-search' => true], 'required' => false, 'label' => 'group.label',
+            ->add('group', StructuralEntityType::class, ['class' => Group::class,
+                'required' => false, 'label' => 'group.label', 'disable_not_selectable' => true,
                 'disabled' => !$this->security->isGranted('change_group', $entity), ])
 
             ->add('first_name', TextType::class, ['empty_data' => '', 'label' => 'user.firstName.label',
diff --git a/src/Repository/StructuralDBElementRepository.php b/src/Repository/StructuralDBElementRepository.php
index fb709f1d..18e11f58 100644
--- a/src/Repository/StructuralDBElementRepository.php
+++ b/src/Repository/StructuralDBElementRepository.php
@@ -46,7 +46,27 @@ class StructuralDBElementRepository extends EntityRepository
      */
     public function findRootNodes() : array
     {
-        return $this->findBy(['parent' => null]);
+        return $this->findBy(['parent' => null], ['name' => 'ASC']);
+    }
+
+    /**
+     * Gets a flattened hierachical tree. Useful for generating option lists.
+     * @param StructuralDBElement|null $parent This entity will be used as root element. Set to null, to use global root
+     * @return StructuralDBElement[] A flattened list containing the tree elements.
+     */
+    public function toNodesList(?StructuralDBElement $parent = null): array
+    {
+        $result = array();
+
+        $entities = $this->findBy(['parent' => $parent], ['name' => 'ASC']);
+
+        foreach ($entities as $entity) {
+            /** @var StructuralDBElement $entity */
+            $result[] = $entity;
+            $result = array_merge($result, $this->toNodesList($entity));
+        }
+
+        return $result;
     }
 
 }
\ No newline at end of file
diff --git a/templates/AdminPages/EntityAdminBase.html.twig b/templates/AdminPages/EntityAdminBase.html.twig
index f3d4e23a..d6e28ef4 100644
--- a/templates/AdminPages/EntityAdminBase.html.twig
+++ b/templates/AdminPages/EntityAdminBase.html.twig
@@ -67,9 +67,11 @@
                             <div class="tab-pane active" id="home_common">
                                 {{ form_row(form.name) }}
                                 {% if form.parent%}
-                                    {{ form_row(form.parent) }}
+                                   {{ form_row(form.parent) }}
+                                {% endif %}
+                                {% if form.not_selectable is defined %}
+                                    {{ form_row(form.not_selectable) }}
                                 {% endif %}
-                                {{ form_row(form.not_selectable) }}
 
                                 {% block additional_controls %}{% endblock %}
 
diff --git a/templates/Form/extendedBootstrap4_layout.html.twig b/templates/Form/extendedBootstrap4_layout.html.twig
index 4581f1f2..e8fefb43 100644
--- a/templates/Form/extendedBootstrap4_layout.html.twig
+++ b/templates/Form/extendedBootstrap4_layout.html.twig
@@ -12,4 +12,21 @@
 
 {% block form_group_class -%}
     col-9
-{%- endblock form_group_class %}
\ No newline at end of file
+{%- endblock form_group_class %}
+
+{%- block choice_widget_options -%}
+    {% for group_label, choice in options %}
+        {%- if choice is iterable -%}
+            <optgroup label="{{ choice_translation_domain is same as(false) ? group_label : group_label|trans({}, choice_translation_domain) }}">
+                {% set options = choice %}
+                {{- block('choice_widget_options') -}}
+            </optgroup>
+        {%- else -%}
+            {% if use_html_in_labels is defined and use_html_in_labels %}
+                <option value="{{ choice.value }}"{% if choice.attr %}{% with { attr: choice.attr } %}{{ block('attributes') }}{% endwith %}{% endif %}{% if choice is selectedchoice(value) %} selected="selected"{% endif %}>{{ choice_translation_domain is same as(false) ? choice.label|raw : choice.label|trans({}, choice_translation_domain)|raw }}</option>
+            {% else %}
+                <option value="{{ choice.value }}"{% if choice.attr %}{% with { attr: choice.attr } %}{{ block('attributes') }}{% endwith %}{% endif %}{% if choice is selectedchoice(value) %} selected="selected"{% endif %}>{{ choice_translation_domain is same as(false) ? choice.label : choice.label|trans({}, choice_translation_domain) }}</option>
+            {% endif %}
+        {%- endif -%}
+    {% endfor %}
+{%- endblock choice_widget_options -%}
\ No newline at end of file