Very easy with Pan/Crop. Place both video clips on the timeline on two separate tracks, one above and one below. Open up Pan/Crop on one of the clips and drag the dashed cropping rectangle out larger to make the image smaller (the cropping rectangle represents the output frame), and then slide the rectangle left or right to move the image right or left. Do the same thing with the second video event, but moving it the opposite directly.

You can also do this with Track Motion, but keep in mind this affects the entire track, not just the clips in question, so if you have other clips in your project that you don't want to do this to you either have to use keyframes, or put them on yet another track.