What martial arts training covers restraining, or fighting , those with martial arts training?

I took non-violent crisis training years ago. It taught me how to break a hold, but not several at once. What training goes to restraining, or breaking a hold , from those with martial arts training? Also how does one break a hold from someone, or several, who know what they are doing? Do police and militia have training to use against other police s.w.a.t. or militia.