There are two ways to
Depending on whether you entered a total or contributing forecast, the relevant forecast row will automatically calculate revised figures. For example, let's say you enter a Worst Case of 2,000 USD as a total forecast for your region; in this case, the value of Worst Case for This Region will update so that forecasts for the individual region and the sub-regions equal the total forecasted amount.
The forecast can now be viewed and edited on the Services Forecasts page, assuming you have permissions.
Related Concepts
Services Forecasts Overrides Overview
Related Tasks
Viewing the Services Forecasts Worksheets
Changing the Forecast Time Period
Entering a Forecast for a Project
Overriding a Services Forecast
Reference