It's a lot like Alexandria but bigger and better developed. Jesus is a recruiter for them and he helps establish a network of trade between the two communities. Maggie ends up becoming the leader of the Hilltop.
Jesus doesn't necessarily run it. Jesus does for the hilltop what Aaron and Daryl do for Alexandria. Gregory runs the hilltop and then Maggie takes over leadership from him when he tries to kill her and has Gregory hanged.