I think that what you're suggesting is something along the lines of small multiples (also know as multivariate reporting)?
Power BI does not have support for this, although there are a few custom visuals in the maretplace that do offer it (but not for pie charts). It is one of the most highly requested features for Power BI but there's no sign of it yet.
If your 22 location values are known and are not likely to be dynamic, the simplest (not necessarily fastest or easiest to maintain) way to to this without any development would be:
- Add your visual to the canvas with measures
- Add your location field to the visual filters
- Select your first location in the filter
- Copy/paste the visual and change the filter of that one to match the second location
- Repeat step 4 for all other locations
There is a better guide published by the Power BI team here.
Another alternative is to consider if a pie chart is the best visual for what you're trying to communicate. Pie charts are often not regarded as an optimal way of showing proportion, when a bar chart might suffice. This is obviously your call, but if you can change your visual type, then the 100% Stacked Bar Chart might fit your needs.
Hopefully this helps you out - it's one of the killer features missing in Power BI that should be easy, but currently isn't.
Regards,
Daniel
