Requisition approval process tweaking

Hi Gurus,

I have a requirement for the Requisition approval process as mentioned below.

If User(Internal Employee) A is creating a requisition on behalf of another User (B), then approval process start, system will send the notification to User A’s supervisor as the current process. But is there any way we can start approval process from User (B) and his supervisor hierarchy (similar to expense report)

For Example (Expense Reports): If the user A had access authorization to submit expense reports on behalf of user B, when the user A create expense report and submit, then system will send notification first user B for the approval and then it will go to User B’s supervisor.