This article includes guidance on how to view and edit who has access to a report.
Log in to BI Book with admin rights
Click Company management > Reports > Access List
In the window that pops up you can view who has access to the report as well as revoke the access to the report of either every user (Revoke from all) or only of certain users (Revoke). Note that you can't revoke the access of another admin user. However, if you want to revoke an admin's access to a report you first need to change the role of the user
Granting access to every user can all also be done in this pop-up window (Grant to all). However, granting access to just a certain user can't be done here. Instead you need to go to Company management > Users> Edit
An Edit user window will pop-up in which you can edit the user's role as well as add or reduce reports the user have access to. Remember to click Save when you're done with the edits