Current page's thing in reusable element

[Bruno27]

you should be able to use parent’s group user cause the reusable element is in the page you are working on it right? if you are noit using the element in the page you can not share info
also here a very good post about it:

A guide to advanced use of reusables

A recent thread about the Bubble editor becoming sluggish over time spawned another discussion: reusable elements can speed up the editing of complex pages significantly, but as it was rightly pointed out, they can also make the editing of an app a lot more complicated. Having worked on some very large one-page apps, I’ve become a reusable group proponent by necessity. It’s a fact of life at the current stage Bubble is in, that as the number of elements and workflows increases, the editor become…