Create a new Rule in existing Workflow in Document Approval

Hello,

I am working on configuring our approval workflow and need some assistance. Currently, we have a parallel workflow where:

• If a buyer(any existing buyer) creates a PO less than 500K, it goes to the Associate Director of Procurement and the Director of Procurement with a 1% voting requirement.
• If a buyer creates a PO greater than 500K, it goes to the Director of Procurement

I am trying to add a new rule with the following conditions:

• If the buyer Sam(Only him not all buyers) creates a PO less than 500K, it should first go to Brian for approval and then to the Associate Director of PO.