If you want to superimpose other videos or pictures on the original video, 

using Pic-in-Pic is a good choice

1.Click the Pic-in-Pic button of your material

2.Position, rotation angle and size of the pic-in-pic could be modified in the preview box

3.In the same way, the picture material can be add the same

4.What’s more, you could use Picture-in-Picture to split screen

Join us immediately to edit your wonderful time!