The different projects can be entered here. If a project is linked to a specific space, you can enter it in the space restriction.
In the authorisation roles, you can indicate which spaces are visible or may be modified for a particular role, and for each user, you can indicate whether this information should also be used to filter elements linked to the room. If you have specified for a user that the authorized spaces should also be used to filter linked elements (see User role) then only projects that do not have a space restriction or that have a space for which the user is authorized will be shown.