Web Filtering using AD Group in Source Network

Hi,

I am not sure whether my ways is correct or not. I am trying to setup web proxy profiles and controlling web access for certain AD group.
So, as the print screen attached, i inserted the AD group in the Source Networks for the proxy profile. However, I found that it is not working.
ASG doesn't blocked their web access.
May i know is it wrong to control AD group using this way?

Attached Images

asg.png (39.2 KB)