Thanks for joining us here in the Community, @NOG_T.

Let me provide some information about tracking commissions in QuickBooks Desktop.

You have the option to add yourself as a sales representative. This way, you'll be able to track the allocated commission for each invoice that you're going to process from both Distributor C and Producer B.

To do that:

1. Click Lists on the menu.
2. Select Customer & Vendor Profile Lists, then click Sales Rep list.
3. Click New.
4. Enter the needed information. 
5. Click OK to save.

After that, you can now enter your name by the time you create invoice. Make sure to enable the rep section on the template so it will be visible.

Here's how:

1. From the invoice page, refer to the Formatting section.
2. Select Customize Data Layout.
3. Under Header, put a check-mark on REP. 
4. Click on OK.

Once done, you can now create an invoice and select your name as the sales representative. This way, you can run a report that contains all the transactions where you can get commission and manually compute the commission amount to be paid.

To run the Sales by Rep Detail report:

1. Go to the Reports menu, then go to Sales.
2. Click Sales by Rep Detail.
3. Select Customize Report, then choose the accounting method under the Display tab.
   
   
    
4. Go to the Filters tab.
5. In the Search Filters field, enter and select Transaction type.
6. Under Transaction Type, select Invoice, then click OK.
   
   
    
7. Change the To and From dates, then click Refresh. 

I also, added this article that might come in handy to personalize your report: Customize reports in QuickBooks Desktop.

For future reference, you can also memorize the report so that you'll not go to the same process again, here's an article to help you through the process: Create, access and modify memorized reports.

Let me know if you need more help about this matter. I'll make sure you're all set. Have a lovely day!