**As a** project portfolio manager

**I want to** set project attributes of type hierarchy and Begin of the insertionweighted itemEnd of the insertion Begin of the deletion scoredEnd of the deletion list

**So that I** can more easily add structured information to a project portfolio in a single field.

**Acceptance Criteria**

* When creating a new project attribute, an admin can choose the types Begin of the insertion"Weighted itemEnd of the insertion Begin of the deletion "ScoredEnd of the deletion List"  and "Hierarchy".

* If a user edits a project attribute of those types, a modal dialog is displayed with a tree view of all available items.

* The tree view is searchable.

* The tree view must be multi select, if the project attribute supports it.

* The tree view must be single select, if the project attribute does not support multi select.

* If the user confirms the modal dialog, the selected value(s) must get assigned to the project attribute.