See this blog for Setup Forecast with Revenue Split, this blog will share on using Overlay Splits. To enable Overlay Splits Forecasts, here few things need to perform:
1. Enable Opportunity Team Selling
Search Opportunity Team Settings and enable Team Selling. You can add the Opportunity Team related list to the page layout.
- Search for Opportunity Splits, then click Setting.
- Click "Set up Opportunity Splits" button
- By default "Revenue" and "Overlay" are active, no need to change anything here.
- Click Save button and Enable to confirm.
- You will get an email once Opportunity Splits are enabled.
- Add "Opportunity Splits" related list to the page layout.
3. Enable Forecast
- Search Forecasts Settings
- Select "Enable Forecast"
- Click link "+ Add another forecast type"
- Select "Opportunity Overlay Splits"
- Click OK button and Save button
Now in forecast tab, click gear icon, you should see option for "Overlay Splits"
Once you have opportunity split by Overlay, you will see the number show in Forecast when select Overlay Splits.
In Opportunity Related List
In Forecast Tab
Reference: Overlay Splits Forecasts in Collaborative Forecasts