I am trying to get a combined total trend to appear on my chart for a given dimension.
My trend graph is of a key operating ratio by division over time.
Can anyone suggest the best approach. I've gone about it by adding a "dummy" data source and removed the join on the division dimension being used, and then using the dual axis functionality to get the total trend line to appear.
The issue I am trying to work around is the tooltips - since the tooltip for the total line still refers to the incorrect division. I understand that you can reference the datasource field explicitly but cannot work out exactly the logic to show the correct name for the total trend line.