Not sure how to accurately describe this.

Say I have two different video layers. The video layers alternate between each other in the comp, displaying back and forth (basically, when one layer is showing, the other is cut and only starts when the current layer ends). There is a constant stream of video that alternates between the two files, but when a file isn’t the one showing, it’s cut.

Now say I want to have a different overlay pop up on-screen that alternates between the two video layers... Would it be possible to create an expression to set this up without having to manually cut the overlay in accordance to where my video files are shown?

Something like “if VIDEO FILE NAME 1 is currently being played, display OVERLAY 1” and vice-versa?

I hope this makes sense.