Maximum set &1 for char. 'Partner unit' does not exist in dimension &2

What causes this issue?

You are using maximum set &V1& for the characteristic Partner Unit in
breakdown category &V3&. Maximum set &V1& does not exist in dimension
&V2&.

System Response

All consolidation units of dimension &V2& are considered as valid
characteristic values.

How to fix this error?

If you want use maximum set &V1& to restrict the selection of valid
partner units in dimension &V2&, switch to the global dimension &V2&,
maintain breakdown category &V3& and create the set &V1&.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.