Tableau Server offers various ways in which administrators can set different permissions within for sites within server and within sites. Permissions can be set for specific users, user groups and for workbooks, data sources and whole projects. In addition to these permission settings, Tableau Server also allows for row level security within data sources through the use of a user-based filter.
This is particularly useful for when you have one workbook or one data source but require different granularity of data for specific users. For example, if you had a sales team of 300 people, when they log in to server each member of the team should only be able to see their own data. Or if there were several regional sales manager who should only be able to see the sales for the region.
Row level security solves this issue, as it ensures that when a specific user views a data source or workbook in Tableau Desktop or in Server, they are only able to view the rows of data which they are entitled to.
This process works through first identifying the user and retrieving the user-specific set of entitlements from a list of all entitlements. The data source or workbook is then filtered by these entitlements so that the user can only view specified data.
For more information on Tableau Server Row level security follow these links to the Tableau website:
Row Level Security: https://help.tableau.com/current/pro/desktop/en-us/publish_userfilters.htm