Use this window to refresh the currency values for the activity connections. When using multicurrency budgeting and forecasting and/or project currency you are able to use the same currency rates for these currency types throughout the project. However, in some cases you may need to change the currency rates. Once this is done you are able to refresh the existing budgeted/forecasted values for a particular date.
To make these recalculated values useful in a forecast you need to create a new snapshot capturing the changed amounts and connect it to your forecast.