I'll see if I can paint a better picture here. We'll use IP's, let's
here is the setup.

Network 1

Internal Lan 192.168.x.x
BM Priv
BM Public

Network 2

Internal Lan 192.168.x.x
Firewall (other) Priv
Firewall (other)

Lets say network 1 connects from into a switch and
network 2
connects from into the same switch. This switch then goes
a router at and out to the internet.

If I wanted to filter traffic coming from network 2 from their
using BM, what would I need to do?