Want to create a new condition where it should work for a particular person expense reports report a

Summary: I have a requirement where the approval workflow is created in this way manager have an assistant to approve expense report on his behalf. the assistant is also a delegate (Insert expense report) for the person A,

If assistant enter the expense report the approval will go the person-A's manager,

Here assistant and delegate both are the same person.

We don't want assistant to approve the report because she is the delegate for person-A and assistant for the person-A's manager.

We want to create a rule or condition where only for this particular person-A's expense report should only approved by his manager not the assistant.