There isn't a function that gets the server name. In Custom SQL, it doesn't allow either. So it would have to be connected to a stored procedure or function.
Your stored procedure would be really simple:
where you'd write your select statement, just write
Hi Glen, what version of Tableau are you using? I don't have "Data Connection Name" and am using Tableau 10.1. That would be handy if I have it.
I have just checked, and it has been available since (at least) 9.0
This information is only available (AFAIK) when editing the sheet title. Cant see it anywhere else
All the best
Updated: Just re-checked.
In 9.x it looks that there is the option to show Data Connection Name, but in 10.x it is Data Source Name...