Instead of using a group for the advanced economies, you can use a set.
In the example , I created a set for Advanced Economies and a set for LAC.
You can also create another parameter for the set selection.
Next, you create a calculation isCountrySelected = [Country Parameter] = [Country]
Finally, you create a filter
case [set selector]
when 'Advanced Economies' then [Advanced Economies set]
when 'LAC' then [LAC set]
The advantage of the set here is that it returns a boolean (IN the set or OUT of the set), which allows you to do this OR logic in the filter.
You could not do that with a group since it returns a string.
With this ,you need to have the full Country dimension on the column.
You can also use isCountrySelected on the color shelf to have a separate color for the comparing country.
ComparatorBarGraph(mc).twbx 2.1 MB
Thanks a lot for this help. It works just the way I wanted. Thank you again for helping me understand the SET functionality and stuff.