Since you have your data set up where each year is a separate field/variable (rather than having one field/variable called "Year"), the best way to do this is to use a parameter. Parameters can be used to select different fields in your view through a drop-down box.
See the attached file. In sheet "Parameter Test" you can see how this works. I created:
1. Parameter "Year Selection Parameter" that has every year as a potential selection
2. Measure "Year Selection Filter" which ties the selection you make in the parameter to the data in the field you want to use
3. Dimension "Year Selection Display" which is just for display purposes - it will allow you to see the parameter value in your display
With the parameter control box on the side, it now will select the data you want.
Then to show how these are used in your dashboards, I created 2 new sheets and a new dashboard. Now instead of using the specific year field (like  or ), you use the new field [Year Selection Filter], which will be the selection of the parameter.
In any of these views, you can use [Year Selection Display] in the view to see what you have selected.
FYI, I also removed your global filters, as they weren't filtering anything. Otherwise, this should be what you're looking for, right?
And in answer to your question about assigning regions a longitude and latitude: I am not 100% sure, but I believe this is built in to be the geographic center of the country or region. But someone else may be able to answer that better than me.
Hope this helps!
essai LISTES-fix.twbx.zip 158.3 KB
Merci beaucoup Catherine pour le temps passé.