NPS Gauge Chart

Hello All,

I'm trying to re-create the chart at this site:  https://www.kenflerlage.com/2017/07/creating-nps-gauges-in-tableau.html

But I'm stumped where he creates "a very simple pie chart". How does he get the bottom half of the pie chart to "disappear"?

I have downloaded the Tableau workbook but still can't figure it out.

Attached below is my feeble attempt to follow his directions to that point.

Thanks for any help,

Brian