Hi Lee -
No, you can't. Security can be implemented via User Filters and Tableau Server. Essentially, this is a mechanism that allows you to choose who can see what based on their user name and/or group memebership. You can read about it here: User Filters and Row Level Security | Tableau Software
If you don't have Tableau Server, there's not a great way to do this except to distribute two workbooks - one which contains all levels of the hierarchy, the other which contains only the first X levels. Based on the database that you're connecting to, you might also be able to restrict which rows a user can see using database-based security mechanisms.
Hope this helps!