Hello, I'm in Resolve 16 - in the Fusion tab - and I have one MEDIA IN that I'm applying a Delta Key node to in order to key out a green screen. However I would like to apply another instance of Delta Key in order to grab the edge of the green screen which is a darker value. I can't get rid of it in the first Delta Key node without losing the phone in the hand of the person in the shot. How do I combine these two nodes? I've tried merge but literally nothing happens. Help! Please and thank you!!