VCAs don't move and nest on consoles, generally.
For "nesting" just assign slave tracks to the group's master track and also the master's master if that makes sense to you. i.e. snare top is in "snare" group, "drums" group and in "band" group -this gives you the tree hierarchy of group-inna-group for tracks, but allows you to opt-out of the tree structure if you want to.
Be good to have some ghost fader indication in REAPER, but we manage without it on live consoles,
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