You may want to place the [Volume Discount] Mark
on a Second Axis, and format it's label to the Bottom
(leaving the other labels on Top), then use Dual Axis.
Thanks Yuri.. Great idea.
Actually I tried implementing . In some cases its good but still some issues. I am posting it here if you have suggestions further.
1)As one label is given the formatting down , there is some space below 0 and above axis( Not touching x axis)
2)Legends are double the number
3)Also the main issue is sometimes volume discount is positive(As in the attachment), where the label of base discount will be inside volume discount bar.
I understand that a 'simple' workaround
couldn't run smoothly (because of the data).
May be better to avoid 'stacking' Gantt Marks altogether
(by placing [Category] on Columns, too)?