Org unit &1 not used in integrated cons type &2 and CS org unit &3

What causes this issue?

It is mandatory that org unit &V1& be used in the definition of a
combination rule for cons type &V2& and CS org unit &V3&, however, the
org unit is currently not in the definition.

System Response

The rule has an error and cannot be saved.

How to fix this error?

Include the org unit &V1& in the definition of the combination rule.

Error message extract from SAP system. Copyright SAP SE.