Timeline layering: is it possible to have a shapes overlay another whilst retaining normal layering rules?

To attempt to clarify. I would like the red circle to underlay the green whilst maintaining it's position over the others and keeping the green circles position under all of the other circles.

This is something Escher (look up some of his drawings, especially Waterfall, and Ascending and Descending) could do, but in the real world can’t exist.

You can try, but no matter what you do, the top color is not going to have a nice neat moon shape. It isn't possible, even if you create a custom shape (or state) with a slice of green on the red.

Whether the green is a nice moon shape, or the red is, the dotted area has to be a color, and that changes the effect.