Double Gantt chart header


;How to create a double Gantt chart header as shown in the figure


Gantt doesn’t have a built-in feature to make it work that way. You will need to manually implement a custom solution.
For example, you can return HTML elements in the label parameter in the column configuration:

By applying some styles, you can try to make the elements look like a table.
Here is an example of how it might be implemented: