As per Felix Delgado:
aCM 5.x - Feature Request – Ability to Support a Directory Group within a Directory Group. Nested Folders Like windows explorer:
Hospital 1: - click on this and then you get:
Cardiology
Emergency Services
Then when you click on one of those you get the sub entries. It's a more structured easier to use directory source TMS does this today for video endpoints ex SX units...
This feature is already done.