How to restrict duplicate values in a free text DFF

Summary:

At the subinventory level, we have created a DFF (Descriptive Flexfield) as a free text field. We require that if we enter a value in the DFF field for one subinventory, the same value should not be allowed for another subinventory in that field.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

23C

Code Snippet (add any code snippets that support your topic, if applicable):