Well with more manipulation, I managed to get what I wanted.
Not sure it's the 'right' way but, it works.
The result of the query is for the record source of a combobox.
I wanted the Location ascending, but grouped by the Service Unit and Tribal.
Also note, I didn't want 'Division of Facility Management' at the top, so I had to add an add'l expression.
So I got what I needed but it looks a bit ugly...