There is no driver for you to use in Tableau. Understand, most of the drivers that Tableau has posted on our Drivers Download page are written by the actual database vendors. We wrap our API around what they bring to Tableau and test it. So, it really requires customers asking HL7 for a way for Tableau to interact with the data. You could try using the generic ODBC or JDBC driver. Not sure if they support those two. You could try to write one yourself using the web data connector (which walks you through using our API to connect to data sources that offer web services).
I wish you well and hope you can find a way or perhaps someone else may know a way.