To add/edit/delete nodes, use context menu in chart.
1. Root Items: Right-click blank area on the chart and select Add root items.
Optionally you can select the number of nodes.
(Figure 1 : Charting)
2. Type in the Content box
(Figure 2 : Charting)
3. Child Items: Right-click on the node and select Add Children.
To edit/delete the node, select that action from the menu.
(Figure 3 : Charting)