Although this an older feature that it is new and improved! For policies that have multiple Lines of Business (LOB) with different commission rates each LOB will be added in the policy entry or edit screen, please see the following screen shot. This will replicate in the Billing tab within the Momentum view of the policy details screen. Please notes that the coverages and premium will be added as normal.
From within the policy details screen go to Billing (top navigational menu) > Endorsement Splits. Here the premium and commission split can be entered, and subsequently all other endorsement changes will populate to Endorsement Split tab to add the correlating commission, see screenshot below. In the near future, all of this data will also be pulled into a report.
Let us know if you have any questions.