Tableu product currently does not log any activity related to permission changes. These are important events which help us to indentify the permission changes for Tableau objects and also helps us to maintain an audit log from security perspective. Without logging it becomes difficult to track any permission changes over time.
Few examples of events to be logged
1. Providing users/groups access to Tableau objects
2. Revoking permssions to Tableau objects
3. Change in permissions