We have a requirement to validate the person number such that first three characters is based on BU.

Person Number generation is configured to be manual. Here we have a requirement to validate the person number such that the first three characters should be capital letters based on Business Unit, and the next three characters should be Numbers. Total Six characters.
Example: if Business Unit is “X” then person number should be “ABC123”
If Business Unit is “Y” then person number should be “XYZ123”.

Is there any solution to achieve this?