Disaggregation - Filters in Worksheet - Proportionality Logic

Hi,

I would like to understand how disaggregation takes place in demanta under following scenario.

Imagine we have COUNTRY GROUP --> COUNTRY are two levels. COUNTRY GROUP is higher level

As members

COUNTRY GROUP  - EMEA

COUNTRIES -- UK, FRANCE, GERMANY

Now we have a worksheet in which we are displaying the forecast at COUNTRY GROUP level but with FILTER on COUNTRY which selects UK and FRANCE

Forecast override has proportionality series as sales history.

Now when we override the forecast at COUNTRY GROUP level with filters on worksheet, does the dis-aggregation takes place only among the countries that are filtered out? or does it dis-aggregate to all members under country group which are not part of filter? My understanding is it should dis-aggregate among the countries that are under filter.