Top 3 values in a row in Table

My advise would be to use the Query Editor to reshape the data in a format that makes it much easier to achieve your objective. Instead of:

Name             Product 1          Product 2
Salesman 1       200                300
Salesman 2       20                 450

you would want:

Name            Product           Amount
Salesman 1      Product 1         200
Salesman 1      Product 2         300
Salesman 2      Product 1         20
Salesman 2      Product 2         450

You can use "Unpivot Column" functionality in the Query editor to achieve this. Once you have the data in this format you can use the DAX TOPN function.