It sounds like you are asking a licensing issue to allow users to access a .mdb file from Tableau Desktop. These users should contact Tableau via the Contact Us link at the bottom of this page to discuss licensing options with a Tableau Account Manager.
I suspect this is a different issue... .mdb files are Microsoft Access databases and Microsoft does not provide a driver for Macs and we don't have a generic ODBC connector on the Mac to use with the few bits of third-party software that can connect to .mdb files.
Assuming this is the case there are three workarounds:
1) Create a Tableau data extract of the .mdb file prior to exporting as a Tableau Packaged workbook. Tableau for Mac has no problem reading extracts whatever their source.
2) The original issue is creating an aggregated source by using Tableau's Export Data function that creates the .mdb. It could be possible to avoid that manual step by using something like Level of Detail expressions or table calculations in Tableau that can be nested on top of regular aggregations (thereby creating aggregates of aggregates). Without knowing more about what's happening in the exported workbook I can't be sure if that's the way to go, so there's one more workaround...
3) Alternatively to #2, an aggregated data extract could be created and avoid the need for a manual export.