eb3bkw is right. Only have the 1 TG in the GCL (Groups Receive List) If you have many TG in the list you apply -- you will hear all those TG's on 1 channel. If you turn GCL off..you will only hear private calls to you.
How ever many TG's you have in list "1" is what you will hear. Make another Group List with just the one TG that matches the contact group you are tx'ing to, and name it "TG ?? only".