Vacation rule: Is it possible to restrict the list of users available as delegates?

Summary:

Content (required):

We are looking for a way to restrict user list available in 'Delegate to' based on the employee Business Unit when employees are enabling their vacation rules, to make sure they are not delegating approvals to someone who doesn't have rights to approve.

Is it something that can be done?

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

22A

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