Floating menu - layout

Hallo,
Is there a way to get the layout as illustrated below? I want to put the cyan button under the blue one. (not too sure if the column breaker item works at all ?

right now you'd need to position that cyan button absolutely (that will only work if the size of the menu is fixed)

Sub layout containers are coming in a few weeks, I'm currently thinking about how to integrate such.

ah yes, thx, there are so many options ....