You have the following dataset.

To create a boolean calculated field to place on the data source filter, you should use the formula USERNAME() = [Tableau_user]. This formula will return TRUE if the current Tableau user name matches the value in the Tableau_user field, and FALSE otherwise. You can use this formula as a data source filter by dragging it to the Filters shelf and selecting TRUE from the menu. This will filter the data to show only the rows that are relevant to the specific Tableau user.

The other options are not correct for this scenario. NAME([Tableau_user]) is not a valid function in Tableau. ISFULLNAME([Tableau_user] ) = USERNAME() is not a valid expression in Tableau. ‘S’ + STR([Sales]/1000) is not a boolean expression, but a string expression that converts sales to thousands with a prefix of “S”. References: https://help.tableau.com/current/pro/desktop/en-us/filtering_datasource.htm https://help.tableau.com/current/pro/desktop/en-us/functions_functions_logical.htm#USERNAME https://help.tableau.com/current/pro/desktop/en-us/calculations_calculatedfields.htm

In Tableau, the USERNAME() function returns the username of the user who is currently logged in. To create a filter that only shows data relevant to the logged-in Tableau user, a boolean calculated field can be created to compare the current username with the usernames listed in the Tableau_User_Name field of the dataset. Therefore, the correct formula for this filter is USERNAME() = [Tableau_USER_NAME] , which will return true for rows where the Tableau_User_Name matches the current user ' s username.