Currently, if I have a variable in detailSection1 like this (click here for screenshot).
I cannot use that variable to build a group in Group Collection Editor like this (click here for screenshot).
Variables can often contain complicated business logic that would be cumbersome to have to reproduce in the group collection editor. Also, variables might reference other variables which can make the logic even more complicated.
It would be nice to be able to simply reference a variable when using Group Collection Editor in Report Designer.