Good Morning Roushan,
There can be a couple of ways to do this, but here is a method with minimal steps:
Go to Sheet 1
<ctrl>click on the SUM(Sales) Measure on the Rows Shelf and drag a second copy to the right.
Right click on the second copy and choose 'Quick Table Calculation' and then 'Rank'
You should see the second axis assign an ascending value to each customer 1,2, 3, etc..
Then rick click the second copy of SUM(Sales) again, and select 'Discreet'. the pill will change to blue and move to the far left of the Rows shelf.
Drag that blue, discreet pill to the filter shelf, and select the discreet boxes 1-10 with a check. click 'apply' or 'ok'.
That should work, but test. Looks like you have fewer than 10 customers in Mongolia and Nepal, so obviously you won't have 'top 10' in those selections.
Attached iss the workbook with solution applied.
If you found this response helpful and/or it solved your problem please mark it accordingly!
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Comm3_Solved.twbx 1.3 MB