Brokers, or commercial real estate agents, are most commonly paid a commission upon the signing of a lease. Most brokers are 100% commissioned professionals and will pay varying splits to their designated broker/brokerage firm.
The commission is paid by the owner of the building and is typically paid half upon lease execution and half upon tenant occupancy. The rates vary by market and even by landlord.
If you used the listing broker as your own agent and secured space at the listing broker’s property, your agent will likely be making a double commission. In this case, there would not likely be another agent to share commissions with.