Maintaining Multiple Dashboards

it would be based entirely on the data, let's say if you manually prefiltered the dashboard for person A and B.  If you refresh the data - would the new data be filtered automatically? because usually prefiltered only filtered the current data dashboard and you will have to redo the process for refreshing if you don't have the managers db link properly to the rest of the database.

To make it less complicated, do you have a new column for managers' names and are able to allocate data according to each one? That way you can filter by manager per dashboard without worrying about new data not getting filtered.  If you do have that column, should be fairly easy to filter within power bi service filter tab and hide the manager filter column and make each dashboard for each manager. additionally, you can add an overview dashboard for the master user with a dropdown to filter specific manager .