It's possible using custom polygons that you may be able to this, but I'm not a polygonist so I won't attempt to steer you in any meaningful (or less-than-meaningful) direction. Therefore, I am looking at things from the tooltip point of view.
In the attached, I modified the field used to show [Country] with a calculated field that notifies the observer that the value should be Sudan & South Sudan. Perhaps it could help.
Tooltip Possibility.twbx.zip 166.9 KB
This is a post I have been expecting now for quite some time. I'm glad you've brought it to the communities attention.
This is a topic I have been pushing for quite some time in the Tableau mapping community; namely, that all mapping needs to be dynamic, updateable, accurate: especially the base layer. Urban Mapping, the 3rd party mapping provider to Tableau use a limited zoom enabled OpenStreetMap as a base layer. But foreground data can be historical - e.g allowing for the page function to work. There will be boundary changes in the future, just like the past. This is why I don't use filled map mark type.
A usecase example - the British Empire
Anyway, back to your question. Here's the shapefiles you'll need. Last update of these files Dec 2011. The cloudmade files are in WGS84.
In cloudmade SHP files, there is usually a mix of polygon, line and point shapefiles. You'll need path order for Poly and Line, but not point.
Ingest the shapefiles into Tableau using:
ESRI + ET Wizards
Left Outer join your data set to the relevant feature file (DBF)
Thanks Allan and Andy.
This is helpful. I have already used strategy suggested by Andy. I will definitely try Allan's approach as well.
Further more, tableau should not make it very complex to use the layers and tiles generated from other software. Tableau has lots of nice feature. If we could bring map tiles from other sources, then it would be helpful. For example tile mill creates beautiful map tile. If we could import tilemill ( and the similar software) generated map as the layer then map would be beautiful with lots of graphical and interactive features provided by tableau.