How to route the Intercompany Batch for APproval based on User who submitted the Intercompany Batch

Business Requirement: Any Intercompany Batches submitted by "User A" should go to "User B" for approval.

We have to create the above in the Provider Organization that if User "A" submites the IC Batch , It should go to User "B" for approval

But if any user other than User A submits the journal submits the IC Batch it should go to "User C" for approval.

I was trying to find the component which will provide me access to the user submitting the IC Batch

Please advise me which component I should use on the Provider side to access the name of the user submitting the IC Batch so that I can build the rule?