Showing % of total share for top ten buyers

Showing % of total share for top ten buyers

Hi Guys 

I am trying to generate a report for Top 10 buyers and using the default Top 10 filter. But when I try sum > % of total, it only considers share among the top 10. 

I want to show the buyer's share of the total amount sold

E.g. 
Total Sales: 1M
Top ten Buyer total sales: $500K
Top Buyer sales: $50K

The chart should show the percentage of shares the buyer has as 5%, while the chart shows 10% because it takes the total of the top 10 based on the filter and not the sum of all buyer amounts. 

I tried multiple things in the chart, but I'm not sure how to overcome this.

Any input or details of what can be used would be very helpful.