Hi Joel,
Unfortunately that is not possible withing the FS UI.
However, being that you are using Bottom-Up, it is fairly simple to implement it in coding. It would require a few calls to PROC TIMESERIES to accumulate the lowest-level forecasts to each higer-level of the hierarchy. You can look at the code that generates the data for the project as an example.
For example, if you open "CREATE_PROJECT_IMPORT_DATA.sas" in your your project folder, look at the code that follows this comment:
*----------------------------------------------------------------------
* level: _top
*---------------------------------------------------------------------;
There will be one run of PROC TIMESERIES for each level of the hierarchy. You need to replace the lowest-level data with the lowest-level forecasts, e.g. replace "data=_HPF2.DATA" with "data=_HPF2.OUTFOR", where "_HPF2" is the library that contains your lowest level of the hierarchy.
Then you will need a VAR statement to accumulate your PREDICT variable, e.g.
var predict /acc= AVERAGE ;
Store the results in a data set using the OUT= option on the proc statement. This will give you the accumulated prediction for each level of the hierarchy. Since now each level is generated directly from the lowest level, it will be properly weighted by the number of observations in each group.
If you have questions feel free to contact our tech support and we will assist you.
Best regards,
Michele