Don't really know how to use the indexed-repeat function well

Niger_Caregiver_updated.xls (152.5 KB)
I am working a questionnaire and i am having errors coming up telling i need to use indexed repeat and really not much idea on how to use it. i referenced a couple of questions to show in a repeat group it worked well, but when i referenced the same questions in the 2 repeat group then i get the error message. pls help