Can you try to map as below and try it if that can help you:
Itemnumber in excel sheet -> ItemNo. in PIM
Productnumber in excelsheet -> ProductNo. in PIM
Productnumber in excelsheet -> Higher Level Product field under References category on Item Entity.
(Note relationship between cross catalog may not be possible)
- Lokesh Kumar
sorry for late response. Now we found the time to test your solution. Unfortunately, it is only possible if we import it into the product master but not in a supplier catalogue.
Is there any other idea?