How to exclude Broker's commission from gross income

[TaxScratching]

Very similar to an earlier question of mine....

The Self employed commission box (020) includes the entire commission (my portion and the Broker's portion, including GST) that I collected as part of my sales person commission for the sale of real estate. So, as a simplified example;

The total commission collected is 10,000. Of that, 7,000 goes to me and 3,000 goes to the broker.

My T4A reports the full commission (10,000). How/where do I deduct the 3,000 so I'm not including that as part of my net income?

Thanks for any help!