Error - different controlling areas

What causes this issue?

You tried to enter the capital investment program position &V4& as
subordinate to, or at the same level as program position &V2&.
However, this is only allowed if both positions belong to the same
controlling area. However, position &V4& belongs to controlling area
&V3& and position &V2& belongs to controlling area &V1&.

System Response

The system does not allow the entry.

Error message extract from SAP system. Copyright SAP SE.