Creating pie chart from calf_pain::<left_or_right>_side?

[PaperOrb]

This is a question rather than a bug report.

I want to create a pie chart that takes 1 singular dataview field (the field will be calf_pain::left_side or calf_pain::right_side) as input. However, I can only get the pie chart to work if there's more than one dataview field (e.g., calf_pain_left::1 and calf_pain_right::1), and it only works if the dataview field contains an integer.

Is there no way to tally up the % of times calf pain occurred on the right leg versus left leg using just a singular dataview field?