Should org-show-hierarchy-above work in combination with tags-todo in the following org-agenda-custom-command?

          ("Q" "Project todos" ( (agenda)  ( tags-todo "PROJECT")  )
           (
            (org-show-hierarchy-above t )
            )
           )

I can set other options, and see that they have the effect that I expect (org-agenda-files, for example).  But setting org-show-hierarchy-above does not seem to do anything for me. 

Thanks,

Nik