Are you describing a split screen? Yes, that's easily done.
If not, can you be more specific or link us to a YouTube example of what you're trying to do?
If, as Steve and I anticipate, you are talking PiP (Picture in Picture), then the answer is YES. You can Alt-click the Audio of the Clip, that you wish to remove, and just Delete it. Don't worry, you have NOT Deleted it from the source Clip, just from that instance of it on the Timeline.
In later versions of PrE, there are even PiP Presets. Now, I choose to create my own, and there are several ways to do this, depending on exactly how you wish the PiP to display. It can also be animated with the Effects>Motion>Scale and Motion>Position.
If you want something more involved, like this PiP appearing in a TV set in your video taped scene, then you will probably want to look into Track Matte Keying.