Adding Sub-Group by Group RH-SSO Rest API is not working

Issue

Having successfully exported groups from one RH-SSO instance and parsed it. I am attempting to import those same groups into another instance of RH-SSO (the same version as that from which groups have been exported). However, one of the groups being imported has a nested array of sub-groups that are ignored during the import, so all that happens is that only top-level groups are being imported.