ok, Airwave allows you to move folders (with devices in it) to another folder
So let's say you have
Top -> Folder_a
you want to move Folder_a to Top -> Client_A -> Folder_A, you can do this.
It's not intuitive but if you click on Aps/Devices -> Up
Expand all, scroll to the bottom, edit Folder_a (using pencil), then move it under the appropriate folder....