Open the Filter Menu and head to the Brokerage Filter
From the “BROKERAGES” filter start typing in a brokerage name. Select it from the list once it appears.
You can also customize your filters and add 'LISTING AGENT/BROKERAGE'. From here you can enter Brokerages or Agents and search directly on the Search page.
Note: To search for an agent outside your firm, use the "Agents" filter and type in the agent name.