We have a multi-tenant, single db application where some customers have expressed the desire to get direct access to their own data.
I have been suggested looking into Azure Data Sync to achieve a setup where each of the customers get their own Azure SQL instance to which we setup a one-way synchronization of their data from the master database.
I managed to find some documentation on this, but one I got around to try it out in a lab setup, it looks like the ability to filter rows in the sync job has been removed in a later iteration of the Azure Data Sync service.
Am I wrong or is that feature really gone? If so, what would be your suggestions to achieve something similar on Azure?
You cannot filter rows using Azure SQL Data Sync. However, you can build a custom solution based on Sync Framework as explained here.