I am trying to achieve something like what is reported in this post (group by two columns in ggplot2), but with an additional feature.
I am currently creating my highchart grouping by 2 factors: this solution is working just fine.
What I would like to achieve is: I would like to stack the area chart by only 1 of the 2 factors, and use the other one to have 2 overlapping "stacked" area charts
Do you have any clue how to make it?
Best, Lorenzo