How do you use the comparison view to compare different tracks in a multi camera setup where each track contains a different camera angle? Both the reference frame and the current frame shows the video on the top track. I need one of them to show a different track so I can color match the cameras.
Comparison view isn't exactly set up for multi-cam. So best bet would be to reference Angle A at one point in the edit, and angle B at another point in the edit, make your color adjustments, and then copy those effects onto the multicam master clips so they span across your projects.
Justin's right. Of course, there's been numerous requests to be able to set the track for the reference and live clip separately. Hasn't happened.
With multicam work there's an easy process though. Put one clip of each camera on a sequence. Do your neutralization of each clip to get a decent tonal and saturation balance throughout each image ... with no color casts on neutrals.
Then do the matching process using the Comparison view, maybe even 'apply match' if it works well.
When you have each clip matched ... then simply go to the Effects panel, right-click/copy the Lumetri effect for that clip. Now select the Source tab right under the Lumetri panel title. Go into the Effects Contro Panel for that "Source" tab and paste (Ctrl/Cmd-V). Now you've applied that color work to every instance of any part of that clip in the sequence.
Go back to the 'normal' timeline tab for the clip, and delete the Lumetri of course. And do this for all clips involved.