Is Form filterng on Workarea possible?

System

TS 6.1

Is it possible to restrict the available Forms to particular workareas?
I've a separate workarea for TFO and I dont want the author to see any templates for this workarea.
Currently in CCStd the author is able to see all the forms in all the branches and workareas.
The author is going to have access to both the workareas (normal and the one for TFO).
I tried directory dir-regex, but it didn't work.

Any help is appreciated.
TIA