Can I do a PIP with a Green Background?

Hello,

I have a video shoot over the green background and I replaced the background. But toward the end, I want that package (video with green background + digital background) to be as PIP in another image. Can I do that?

Because I can do either replace background or PIP, but I don't know how to do both (If possible).

Thanks,

Jorge

PS: I'm using iMovie 10.2.2