**Figma**

https://www.figma.com/design/6RzNWrc8jpqhE7jpaCXsGB/Multi-project-selector?node-id=350-68685&t=z0mZO4YlzQSA6XWq-0

**Acceptance Criteria**

* The **Add Projects** button opens a modal

* User can search and select projects one Begin of the insertionbyEnd of the insertion Begin of the deletion beEnd of the deletion one

* Already previously added projects are disabled 

* The form shows **Include sub-projects** checkbox

* When this option is activated we will add all sub-projects of submitted projects to the project attribute

* (This might need limitations on how many can be processed at a time)


**Technical info**

After the merge of PR [https://github.com/opf/openproject/pull/15480](https://github.com/opf/openproject/pull/15480) the autocompleter can be used for projects and allows the definition of **disabledProjects.**

```text
the_form = Class.new(ApplicationForm) do
form do |f|
f.project_autocompleter(
name: :id,
label: Project.model_name.human,
visually_hide_label: true,
autocomplete_options: {
openDirectly: false,
multiple: true,
focusDirectly: false,
dropdownPosition: 'bottom',
disabledProjects: Project.visible.take(10).pluck(:id).to_h { |id| [id, ""] }
}
)
end
end
```