Way to change layer of reference clip in comparison view?

[default8zxxv2gexklq]

I feel like the colour grading tools in Premiere have improved immensly and it's getting to the point where I want to finish shorter broadcast projects in Premiere instead of sending them to Resolve for colour grading. However, the main stumbling block I'm encountering is an efficient way to have two shots set up side by side for comparison. The equivalent in Resolve would be to use 'Stills'. 

Specifically, I'm trying to use the Comparison View in the Colour panel of Premiere to match different shots from a multicam shoot from within a multicam timeline. But I can't find any way to make the reference clip use a different layer (in the same timeline) for a source. Am I missing something? 

Ex., Layer 1 is the wide so it makes sense to colour that first. I disable the layers above it to make it visible, and grade it. Then, enable the second layer (mid shot) to grade that. I want to compare it to the wide shot I just graded, but how can I do so without toggling the layer on/off? Is there a shortcut to throw it up in the Source monitor, if not in Comparison View?

Thanks for any tips.  

[R Neil Haugen]

Don't grade multicams like that.

Grab the original clips, make new sequence. Probably with your 'key' clip at the beginning.

Now just grade down the sequence, matcthing to the original in Lumetri.

Now copy each clip's Lumetri effect in the ECP, paste it on the clip in the bin.

Delete your temp grading sequence.

This applies the Lumetri as a "source effect" so any portion of that clip, anywhere in the project, gets that grade.