Certainly I've heard "the guy behind the guy," but not repeated as you have it.
"The guy" is the guy in charge, the big man, the decision maker, etc. "The guy behind the guy" would be the person who helped get "the guy" into power, who helps with his research, his decision making, etc. Sometimes the person who really knows what's going on doesn't have the charisma or the leadership qualities to be "the guy" but he can be the guy behind the guy and still have quite a bit of power.
Once you have more than the one "behind the" the person is making a play of the expression.