7 position switch, only one position active at a time?
You are wanting a push button selector switch that works like the old style car radio channel selector buttons. These are available as a series of push button switches that have an interlock mechanism such that when any one button is pressed it causes any previously set button to pop out. Finding the exact correct thing for your application could be a challenge though.

You may be better off designing a thing with a small micro controller that accepts the necessary switch selector input signals and in turn drives outputs to some electronic signal analogue mux/switches that manage the video signal routing. Then you can have the software control the behavior as needed and the switches can be very simple momentary push button tact buttons.