First I'd like to confirm your requirements.
- You want a bar graph showing the sum of value for category.
- You want sum of value for Germany and France showing in the tooltip.
If so, my solution would simply be,
[Tooltip Germany]: IIF([Country]="Germany",[Value],0)
[Tooltip France]: IIF([Country]="France",[Value],0)
Then drag them into Marks shelf.
You may notice that SUM is automatically added. That's all right.
Then include them in the tooltip.
As for ATTR, here's the description,
"Returns the value of the given expression if it only has a single value for all rows in the group, otherwise it displays an asterisk (*)"
In the bar graph, field country has multiple values, thus ATTR(Country) returns asterisk.
Thanks a lot, it works!!
Ok, very simple;-) Thank you for the help!