Roy, the only way to get that is to create a field that explicitly contains the county names in each region, and drop that field on the Tooltip card. It's hard to see in your workbook (it's trying to connect live to your SQL Server so I can't actually see the data) but it looks like you're using groups to get your regions.
You're also on version 9, which is holding you back. Is there any way you can get to the current version (10.3)? Much better support for custom territories in the 10.x stream.
There are a couple of open ideas floating around to get the functionality you're asking for in Tableau. You might want to hunt around for them and vote them up.
Thanks, Michael. I just need a little clarification. When you say I need to create a field, do you mean a field in the SQL database or a calculated field inside Tableau?
Sorry for the delayed response: busy morning!
The more I think about it the more complicated it gets, but here goes.
The shortest path would be to manually create a 2-column data source that contains the string of county names you want to display. It's low-tech but it's the only way I know around Tableau's "and x more" problem.
Column 1 is Region Name.
Column 2 is the comma-delimited list of counties in that Region
Join this new table to your existing data on Region Name, and drop the County Names field on the tooltip.
Sorry that's not more elegant...
You can disregard my original question, above. I went ahead and created a Calculated Field that checks the region code field and assigns the county names accordingly. Then I dropped the new Calculated Field on the Tooltip Mark. It worked like a charm. No more "and X more". See the image, below, using the same region as in the original image, above.
I know using version 9.0 is depriving me of the use of a lot of new features and fixes. Unfortunately, I work for a state agency and the only Tableau server we have is on version 9.0. So, I am kind of stuck until the IT people get around to upgrading the server. This isn't the first time I have had to come up with a workaround because of my version.
Thanks very much for the help. You hit the nail on the proverbial head. Gotta love these forums - so many great people willing to help out.
Hooray! Glad you got it to work. And I completely get the "slow upgrades" thing.
Congrats for fighting your way past it!