This is a demo tutorial. While there is no step-by-step commentary available (yet), the live demo below is fully functional. Feel free to open it for full source code.
Normally a rollover tooltip would display in the center of a PieChart
slice. This demo shows how you can make it follow the mouse pointer instead.
See the Pen amCharts 4: Slice rollover tooltip that follows mouse by amCharts team (@amcharts) on CodePen.