Message Oracle ORA-36639 - (XSDUNION18) UNIQUE cannot be applied to this concat dimension because leaves workspace object and workspace object share the value number.

ERROR	(XSDUNION18) UNIQUE cannot be applied to this concat dimension because leaves workspace object and workspace object share the value number.
CAUSE	Unique concat base dimensions cannot contain duplicate values.
ACTION	Use MAINTAIN RENAME to change one of the duplicate values and retry.