Accessing Groups via Blueprint? Toggle visibility for everything but player component

Wondering if this is possible, trying to attempt a Akuma style fullscreen kill move.

Basically on input.

A.Change camera fov.
B. Toggle visibility of a fullscreen video playing on a material billboard inside the character controller.

C. What I am not understanding if it is possible to call a group and disable visibility for the entire scene as opposed to each actor.

If this is not possible I could move the actor and camera forward in z space on keypress ( after extending my walking planes forward ) so that nothing else is in the way but that seemed rather ghetto so I wanted to check first.

Thanks.

Ok saw this :

Tried to select all scenery in game and Replace with Composited Blueprint. Results in crash.

Also, upon thinking about the moving characters and camera away from geometry is that terrain collision would be affected so that aint gonna werk.