Line trace is vastly superior to the overlap method. For one thing, your player can’t push the button with their butt 
But, if you want to use a trace, you do have to do it from the player to the object.
A pretty standard way, is to use a blueprint interface to pass the component your player is looking at to the button actor ( or door etc ). If the button decides the player is looking at the right thing, then you can just use your current code to move the button.