BI Connector's plugin for Tableau (beta version) is released. Now you can connect Tableau to OBIEE (and OAC/OAS) via the plugin as well.
Please use the below steps to download the .taco file of the connector.
Step 1: Access the BI Connector plugin in the Tableau Connector Gallery using this link.
Step 2: Sign in using the Tableau account (If the account not yet created, please create a new one). 
Step 3: Click on the "Sign Up for Beta Connector" option as mentioned below:
Step 4: Click on the "Download" button to download the BI Connector plugin (.taco) file.
Now the .taco file is successfully downloaded. The next step is to configure the connector in Tableau Prep Builder.
Configure the BI Connector plugin for Tableau Prep Builder
Step 1: Copy the downloaded BI Connector plugin file (.taco) to “C:\Users[Your Windows User]\Documents\My Tableau Prep Repository\Connectors”.
Step 2: Restart the Tableau Prep Builder.
Step 3: Start Tableau and under Connect, select the BI Connector. (Note: You'll be prompted if the driver is not already installed)
If you haven't installed BI Connector in your machine already, please refer to the BI Connector Installation Guides.
Please refer to the below articles for using the plugin to connect to your OBIEE.
Connect Tableau Prep Builder to OBIEE Subject Areas
Connect Tableau Prep Builder to OBIEE Reports
If you have any questions or issues creating a report, we are just a click away. Contact us at [email protected] or file a ticket at the support portal.