Can I map one IDP group to multiple business units in SAML?

In short, no, using one idp attribute to map to many groups is not possible, example:

• To map the same group to more than one Business Units is not possible, since the groups are keys values and unique, they can’t be duplicated to allow more than one IDP attribute.

A valid configuration would be:

   // Custom Values, mapping group names with (used as keys in the configuration map businessUnitsMapping) to Irius business units refs (used as values in the configuration map businessUnitsMapping)
                businessUnitsMapping = [
                    'Your_group1': 'testers',
                    'Your_group2': 'managers',
                    'Your_group3': 'developers'
                ]

But the following configuration would not be possible:

   // Custom Values, mapping group names with (used as keys in the configuration map businessUnitsMapping) to Irius business units refs (used as values in the configuration map businessUnitsMapping)
                businessUnitsMapping = [
                    'Your_group': 'testers',
                    'Your_group': 'managers',
                    'Your_group': 'developers'
                ]