In military training aircraft with a tandem seating configuration, with the instructor pilot in the back seat and the trainee pilot in the front seat, is the ejection system ever set up so that there is a mode where the back seat occupant can eject both pilots, but the front seat occupant can only eject himself/herself?
Obviously, I can't answer with certainty about what might exist, but as far as I know, NO. This would make no sense, as once the pilot is gone, why would the rear seat occupent want to hang around?
In the F-4 Phantom, (USAF versions), there was a switch in the rear cockpit (called the Command Selector Valve), that controlled whether or not the front seat ejection sequence would be triggered when the rear cockpit occupant initiated an ejection.
But the rear cockpit ejection sequence was always triggered if the front seat occupant ejected.
Regardless of who initiated the ejection, the rear seat would be ejected and depart the aircraft first, followed by the front seat 2 seconds later. This was to avoid the front seat rocket motor from frying the rear seat occupant.