Hi, I think I can explain myself using the example you have on your documentation page for Multiseries stacked column 2D charts:
Beside the labels you put on that chart, I'd like to print the legend "Products" and the legend "Services" for each year to fully explain that left column is for products and right column is for services. I tried to add seriesName=Product on corresponding high-level dataset (as shown in attached file) and didn't work.
If not possible, those legends could be also on top of each bar (together with $51M, $56M, etc.) but I don't want to erase those numbers (the sum of each column)
Regards
DRios
P.S. Sorry for not posting my own code but since I'm dealing with php and mysql I think it's too much messy
Hope with this example my request is clear