Note that, if you read most of the linked articles and comments, you'll see that this chart is 99% a bad idea. Never the less, I did notice that in the article Chandoo provided a link to a forum thread. Due to a forum migration last year, that link is broken. The correct link to instructions on the file is here: http://chandoo.org/forum/threads/multiple-pie-chart.7343/
Again, and I can't emphasize this enough, this is a terrible idea for a chart IMO. Using columns/bars would be a much clearer alternative usually.