[Orgmode] Any way to include filetags in tags completion?

[Matt Lundin]

Hi everyone,

I've searched the org-mode variables and can't seem to find a way to get
filetags included in tags completion. In other words, when I press "TAB"
to see the org-global-tags-completion-table while entering a tag or
filtering for tags in the agenda, only tags associated with headlines
are offered for completion. Is there a way to include filetags in the
completion table?

I ask because I frequently use filetags (such as "finances" and
"household") to filter the agenda and would prefer (lazy emacs user that
I am) not to have to type the entire word.

Thanks for your help.

Matt