How can I limit access to streaming Audio/Video to only those users in
a
group?

Currently, I have the following Exceptions in my BM3.7 SP2 server:

1. - REALTIME-ST-OUT Interfaces: (Source) Private (Destination)
Public
Packet Type: TCP Src Port: 1024-65535 Dest Port: 554
Src Address: Any Dest Address: Any

2. - REALAUD-ST-OUT Interfaces: (Source) Private (Destination) Public

Packet Type: TCP Src Port: 1024-65535 Dest Port: 7070
Src Address: Any Dest Address: Any

There aren't any Access Rules to setup that affect this that I know
of.