Field &1-&2 cannot be substituted by &3-&4

What causes this issue?

You want to substitute field &V4& from table &V3& for field &V2& in
table &V1&. However, field &V3&-&V4& is not transferred to
substitution, since it does not belong to a Boolean substitution class.

System Response

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

How to fix this error?

Use search help to choose a field that belongs to a Boolean
substitution class.

Error message extract from SAP system. Copyright SAP SE.