@Adom, you could use this sample XLSForm that illustrates how to link a form dynamically within a group.
Reference XLSForm (within group):
Round 1 (Within Groups).xlsx (15.2 KB)
Reference XLSForm (within group):
Round 2 (Within Groups).xlsx (11.9 KB)
We will be updating this sample XLSForm file within the article soon.