When you use an imported data source in your budget or forecast, you can choose which data to use for your budget values:
Please note that if your budget or forecast extends beyond the point to which the above data is available, once you've created your budget or forecast you will need to use the adjustment options to copy the data into the later months.
Elsewhere in the Help Centre:
Select a data source
Update your actuals
Customise your budget, forecast and scenario data