Does Anaplan treat List Subset as a different List?
Because when we changed a module dimension from "Product list" to a subset of "Salable Product list", all the filters got removed.
Yes filters will be removed. Subsets are essentially different lists altogether but linked with original parent list - so if you have to roll up the numbers that becomes easy.
However, Subsets are already filtered version of original list, Now one may argue that in order to remove the zeroes from the view, filters are needed. Valid argument - in that case apply the filter on the subset and not on the original parent list of subset