Squidguard multiple subnet single LAN Interface

[yanafig]

Kindly help on this scenario..

I have PFsense setup as DHCP and Squidguard for 1.0 network
30.0 network is connected to the internet via proxy 1.0
There is route between 1.0 and 3.0 network
1.0 network (some users) is allowed to access social media sites
30.0 network (some users)is not allowed to access social media sites

How can I block or control web access to the 30.0 network? All I can see on the pfsense server is the 1.0 network which I can control using squidguard.
I can see logs of 30.0 network (and others) thru 10.0 but I can't see specific users which I really need. I can't control 10.0 network since other networks are connected to it.