To add new PointMap, PieMap or a ColumnMap series to the map follow these steps:
If you are creating a PointMapSeries, you can define a SeriesGroup by which your data will be grouped. This might come handy if you want to have a different color for every data point in your series.
If you are creating a PieMapSeries or a ColumnMapSeries, you need to define an additional child group, which will be used to determine how the data will be grouped for every data point. The color and count of the pie sectors (or columns when creating a ColumnMapSeries) will be determined by the last child group of defined SeriesGroups. In the most cases you would create one series group without grouping (which will result in a static group) and add one child group, with Groupings set to the field you would like to group by.
Set Size to an expression that will be used to determine the pie sector or the column size.
When all the properties are set, the LocationMapSeries instance should look similar to the following one in the Property Grid: