Using dual axes to overlap bar chart on map and display bar chart as gantt bar chart.
Parameter can be used when [size] mark card is not enough for adjusting bar size.

Steps
1. On map worksheet, drag another [latitude] to row shelf.

2. Right click on the second [latitude] field on the row shelf and select "Dual Axis"

3. On the mark card of the second [latitude],
(1) Select "Gantt Bar Chart" from the pull down list.
(2) Add [quantity] to [Label (Text)] mark card.
(3) Add [SizeAdjusting] field to [Size] card.
※ [SizeAdjusting] is used to adjust bar size. For example, multiply the numeric parameter by the sizing field (e.g., [SizeAdjusting]*SUM([Quantity])).

Please refer to the attached video."Bar on Map Example.mp4" and "Bar on Map Example.twbx" for further details.