Arrange By (Sort By) in the File Tree Panel

I think it'd be great if you could choose how to arrange (sort) the items in the File Tree Panel.

I imagine a pop-up menu (a.k.a. a "dropdown menu" in Windows terms) at the top of the Panel under the "choose folder" pop-up menu, would do the trick.

For me, it'd mainly be for arranging by Kind so that folders will be grouped together for easier navigation.