Summarize By 2 groups

Hello

I can try to put in a filled map the best customer.

My table is:

Country-Customer-Total Sales

Canada-Customer1-100

Canada-Customer2-200

Canada-Customer3-400

USA-Customer2-1000

USA-Customer4-5000

....

In the filled map show:

In canada Customer 1 

In USA - Customer 2

But not is the best custoemer

I can try to use a summarize table, but not work

Any ideas?

Thanks