Connecting Tableau to FileMaker databases has become much easier with the introduction of the FileMaker Data API which can be enabled on a FileMaker 17 Server or later. In addition to enabling the Data API to connect via the FileMaker Server Console, you will need to create at least one privilege set with the extended privilege set allowing for the sharing of file using the FileMaker Data API. Instructions for setting up FileMaker to be used as a data source for Tableau are readily available. Here are some useful links:
As always, it is important to be mindful when you expose data through the FileMaker Data API WebDirect, no matter what technology you will be employing to receive that data. Consider separating out the data that will be exposed into a separate FileMaker file limiting access only to those who require report writing/reading privileges. You may also want to host the data to be consumed in Tableau on a server that is dedicated for API access. If you enable the Data API on a FileMaker server where you are hosting many different FileMaker files, you want to make sure that you aren't inadvertently going to expose data that you did not intend to have visible. Where student or staff data is to be aggregated, you may want to anonymize that data before it gets to Tableau. Also, if you only need the Data for a limited period of time during the year, you may want to turn the API feature off when it is not needed.