Same event, time linked..I'm confused.
If you want to switch between two tracks, you can select a track header and then press the up or down arrow, this will jump from one track to another, but selecting a header is just as slow as clicking one header or another if there are only two tracks.
If you mean that you want the VIDEO to jump back and forth between two tracks, you can do this with transitions, or with the compositing envelope, found by right clicking the upper track, and selecting "insert compositing envelope" and using the rubber band features of the compositing envelope to transition from one track to a lower track.
I'm not sure I understood the question, so hope you understand my answer. :-)