Using instance() to retrieve data from Group questions

I have a 2 surveys (Parent, and Child) linked By using “Dynamic Data Attachments”, I used (repeat_count) typed question , and i am trying to retrieve data of this question into child survey . anyone have an example to share please? as we all know that the submissions appears in separated auto-generated sheet thus I am facing problem with instance() formula

Thanks in advance!

Welcome to the community, @OsamaSalim! We will explore and update the article for this when the system should be able to support this feature.