RealDesk now can map to two different Commission Expense (Cost of Goods Sold) accounts in QBO. This means that you can differentiate between internal commission payments (to your realtors) and external commission payments (for referrals, and cases where you are paying the buying brokerage directly).
If you don't wish to enable this, simply do nothing and you'll continue to use the existing single Commission Expense account.
If you are interested in enabling this functionality, contact RealDesk support and we can set you up in less than 5 minutes.