It depends on which broker.
Your real estate broker (Realtor) is paid through the seller's agreement with his/her real estate agent.
Your mortgage broker - Yes, there are a couple of options when it comes to the loan closing costs.
1) Seller concessions. You ask the seller to caver part or all of your closing costs which includes your mortgage broker's fees.
2) Take a higher interest rate - by taking a higher rate your mortgage broker will be paid YSP or yield spread premium from the end lender which would cover the broker's fees.