You must have the 'JIRA Administrators'  before you can restrict  to selected projects.

You can restrict the projects to which  is available. If you restrict a project from using , this means that you will not be able to select your project from the Classic Planning Board, Classic Task Board, Classic Chart Board or Classic Released Board. Please note that the 'Agile' dropdown menu will still appear on projects that don't have access, but if you try to view any of the boards they will default to the last project that was viewed on that board.

To restrict  to selected projects,

  1. Log in as a user with the 'JIRA Administrators' .
  2. Select Enabled Projects.
  3. Select Apply to these projects. The Project list and projects select boxes will become enabled.
  4. Move projects between the two select boxes by using the << and >> buttons.
  5. Click the Modify button to confirm the projects available to .

Screenshot: Restricting  to selected projects