Ah, now I get it!
I think the columns (at least for me) are shown alphabetically, not sure if you can change that …
One workaround could be to create a link next to your pie chart for every segment that links to another dashboard with those filter entries (as described here: Ability to Link Dashboards (Eg. User list dash -> click ID -> user dash for that id)). Using that you could also define what colums are shown and maybe show a fuller picture rather than only raw data?
Cheers, Eva