Sorry I'm not sure how to describe my issue very well. I have nested data, like so.
Each employee & the projects they're assigned to.
I'd like to show multiple start & end dates on the same row for a project.
It looks like it can be done here: https://www.highcharts.com/demo/gantt/r ... management
But this example doesn't have the nested data.
When I tried to set the 'y' to be the same number, they get forced to be different numbers.