Center object/text in Program Monitor

I am trying to find a way to make sure an object is perfectly in the middle of my program monitor. I know there is a feature that when toggled on you can drag an object or text by clicking on it in the program monitor and it will move perfectly along the axis and pretty much snap around to the middle of the frame. When I say snap I am not talking about snapping clips on the timeline. I've seen this done before but I cannot for the life of me remember how to do it. Help please!!!!