Not sure how to use multiple UV layers on one character So one this character I have a UV layer for the face and one for the body. But when I swap between the UV layers to add more texture paint to either map, the UV layer for the face disappears. I don't really know how to keep both layers visible and active to paint on. 
Here is the face layer displayed, it still lets me add detail to the objects on this layer.

And here is the body UV layer. I want them both active at the same time. And I'm aware that a lot character meshes use both a layer detailing the face, and one for the rest of the body. But I seem to be missing something when it comes to how to use them both... Does it have something to do with the node setup? I tried applying the UV layers as a material to the head and body in the materials tab of the properties panel, but it didn't seem to work. Thank you all in advance for your help and support, you guys rock!
Not sure if you are asking this, but why didn't you connect the respective UV maps to the image textures? Just like its shown in the below image, create a UV Map node for each image texture and connect the respective UV map to the texture.