I need help with making a type of effect - link in the description

[PoisonedSlice]

Here is something close to what you are after. It should give you some ideas (zip with all files is attached):

Split Screen "Mirror" project -- how to adjust positions 'within' a position?

If I understand your objective correctly (that’s a big if, but I’m confident) then crop: source isn’t really what you want to use at the start. In your case, you DO want crop, but crop rectangle - applied as a filter - after the Size, Position, Rotate (SPR) filter. The easiest way is going to be to import your video to V1, add the SPR and the crop rectangle (in that order), then do your SPR keyframing, moving it around as necessary. Once you are happy with your work, only then copy that to V2 a…