On the page you could set up the individual commissions rate for the selected partner.
The Adding and Editing commissions pages are identical except for their names.
Select a paid product from the drop-down list.
After that, set up necessary values in the Commision field. It could be a fixed amount or a percentage of the product cost.
You can set up multi-level affiliate commissions, if necessary. By default there are 2 levels of commissions at the page.
The Save button adds a custom commission to the Edit Commissions page.