Your LOD expression is correct, but the filter does not affect your field (from LOD expression).
Thus what you have to do is to convert the filter to context filter.
To convert to context filter, Right click on the filter field and click on add to context.
Thus the filter would be sensitive to created through LOD expression.
For suppose, if you want to show country sales wrt all selected from filter from same region, then convert filter to context.
You would observe the difference, that the total changes from after and before adding to context.
Hope this helps you.