Currently a Sidebar with multiple detail panels must have enough width to show all the panel items in its navigation bar. We should change this to support narrower layouts (or future additional panels) so that additional panels will be shown in a menu of some kind. This could be achieved using a dropdown on the right side that shows a context menu with additional panels, or could be done in a similar fashion to the the navigation sidebar in the Storage tab which shows the second item as a combo-box style item. (The Storage tab is actually using a Scope Bar instead of navigation items).
<rdar://problem/70619383>