Hi Amine,
You can display all available hierarchies in the InfoPackage in BW. On tab page Hierarchy Selection you can display all hierarchies. Initially you will only see those hierarchies marked as "relevant for BW". However, if you click on (Refresh) Available Hierarchies from OLTP, then you will see all of them. You can now select the one you would like to load in BW and mark any hierarchy as "relevant for BW".
Best regards,
Sander