Unfortunately there isn't a way to do this currently in Tableau, but it is a great feature request. Would you consider adding it to the ideas forum for others to see and vote on? We use that frequently to help ourselves prioritize our work.
Thanks for the great feedback, I really like the idea, that is a very compelling use case.
Associate Product Manager
Thanks for the reply. I have been looking through the Web Connector documentation and I wasn't sure if I was missing something or if The Web Connectors did not support this case. The use case I mention applies directly to tutorial, however for our business, we have several hundred products we summarize on a daily basis, and we can identify problem areas at the high level using aggregated data, but then to navigate to the details is difficult as the detail information for all products would be to large to support. Having a web Service where you can pass the key identifiers for the data you need and letting the web service extract the smaller portion of data would be great.
I am excited that you find this a very compelling use case. I think it could open many more doors for Tableau to make working with Big Data easier...
I will post this on the Ideas Page.