So you have a FPS camera with full functionality, moving around etc works fine, then you enter a trigger box and switch the view to a camera on a separate actor (door) and you want to move that camera around? If trays the case you’d have to treat the door as a separate pawn, so that you “possess” it when entering the box trigger and then it should be able to receive controller input like your FPS camera. You would then “unpossess” when you want to go back to the main character.