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 MapLine object can have a single arrow head. This demo shows how we can create additional Triangle objects to create a two-way arrows on a MapChart.
See the Pen amCharts 4: Map line with two arrows by amCharts team (@amcharts) on CodePen.24419