If you're looking for local administrator accounts for your Windows computers you can use the built-in "Computer: Unauthorized Administrators" report, which can be found under the Reports tab. You can modify which administrators are classed as authorized under Configuration\User Pages in the web console.
If you're looking to find out which users have permissions within your Lansweeper installation you can check out Configuration\User Access & Roles. Any user that is listed under Users and has a User Role assigned to it has some level of permission within your Lansweeper installation. Additionally, users that are a member of AD groups listed in the User Roles section also have access to all permissions contained within the relevant User Role.