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.
This demo shows how we can add Triangle objects as bullets on a TimeLine chart, then use adapters to conditionally rotate them to create directional arrows.
See the Pen amCharts 4: Serpetine TimeLine with arrows by amCharts team (@amcharts) on CodePen.24419