Well looks not so complex, I just do not know yet the proper code.
I need to iterate in each collpasbleset, iterate through checkboxes, then move to next collapasbleset and do the same...

Do I have to do something to see the console log?

I used alert and I get "checked items =0"

I does not seem to go in to the code of "mobilecheckboxgroup.each(function(){"

EXACTLY it works!
Many thanks!

For the benefit of others, code used in the mapping of second level grid (checkboxes)
code
var stringValue = String(value).trim().split("@");
if (stringValue[1] == "false") {
element.hide();
}
/code

I have a grid, to put first level of collabsibleset
and then another grid inside the content arear of collapsibleset, where I put the checkbox.

You have same configuration?

Thanks.

Or how can I prevent item that has "@false" not to be initially returned from the query?