Source: en.wikipedia.org
This sample visualizes the placing of pie charts on the maps. Pie chart is rendered with the age group detais of top 6 largest countries.
In this example, you can see how to render the pie chart as marker in map. Any custom HTML elements can be used as a marker.
Injecting Module
Maps component features are segregated into individual feature-wise modules. To use marker template, you need to inject Marker module using Maps.Inject(Marker) method.
More information on the markers can be found in this documentation section.