AddArrayComponent.... when you thought something was direct and simple, often this solves the issue.
You need to AddItem that includes checkbox ( a suggestion)
agend.AddItem(""&id, fn, BuildSimpleItem("11", "mdi-action-star-rate", fn)) ' that is a checkbox (or something that has a State prop).
Where BuildSimpleItem adds an ArrayComponent (or you add it upon return).
Then, you could check which items were selected.
I do this now on a similar issue (page component) . I do not know if a ABMCombo would/could support this (would be nice). I have a similar issue - but wish to restrict a ABMList within a cell - then scroll for more).
https://www.b4x.com/android/forum/threads/abmaterial-create-toast-with-no-timeout.80429/#post-509838
We are only limited by our (perceived) needs - and the existing framework...
EDIT: I have found that trying to access a STATE prop, issues a FutureChecked and never returns the (checked) state of the component. Only AddArrayComponent resloves this and shows the current state.