How to customize menubar "collapse menu bar medium" items

I'm trying to figure out how to customize what items appear when you change the right side of the menu bar area from full to medium or small. Right now if I adjust it's all the same and I can't figure out where or how to change states for each option.

For example, there are some icons i'd like to remove if to only show for "small" so I save space.

Can't seem to figure this out. Thanks.

Im pretty sure the easiest way to do it is so when you press the small button, it opens a new touchbar group with only the widgets you want. Then to make it full, it opens thew group with all the widgets...etc.

I didn't see a new group - it shows a "named trigger" but I don't see another list to adjust the icons for this small list.