Split screen side by side video effect is as shown below:
In order to create side by side split screen video effect, one of the simple ways is that you may need to place two video clips together as shown below:
Now select a clip as, for example, upper clip. Go to “Effect Controls” and change number in the box with “Position” from 960 to 1920. It will split the screen showing two different screens in the same video.
However, the adjustment of this split screen may not be as you want. So, you may use the “crop” function under “Effects.” Search for the crop function, and drag it to the video clips.
After placing the crop function over the video clip. Crop the areas, by changing the values with the crop function, that you may not want to show in the video for both video clips.
In the figure below, you may have seen, I have slightly changed the crop function related values of the upper video clip (i.e. video clip on the right side in the video panel).
You may also need to adjust the “Position” for appropriate adjustment of the two clips (that are usually comparison to each other). In the figure below, you can see that I have adjusted the “Position” to 1423 for the upper video clip (i.e. video clip on the right side in the video panel).
So, this is the simple way of creating side by side split screen video effect on Adobe Premiere Pro CC.
This effect has been used in my video related to unboxing of MOZA Mini-S Essential here: https://www.youtube.com/watch?v=F_6a9AnoSAY&t=333s