How to apply both a color mask and shape mask to an image/video in Motion?

In Final Cut Pro, you can apply both a color mask and shape mask simultaneously to the same source clip. So you can modify a specific color range in a specific part of the image/video. How do achieve this in Motion?

In the example below, I've dropped down the exposure drastically only to the green part (using a color mask) but only to the part of the clip within the circle (using a shape mask). Both of these masks are applied simultaneously, yet I don't see an intuitive way to do this in Motion like you can in FCP.