Read through the installation guide for BES for Domino and it will tell you what permissions are needed.
Snip from installation guide:
Create a group for BlackBerry Enterprise Server administrators
You must configure the IBM® Lotus® Domino® messaging environment to permit access to specific databases from both the
BlackBerry® Enterprise Server and the BlackBerry Manager. The BlackBerry Enterprise Server can be administered and
managed only by the groups and users included in the BlackBerryAdmins group.
Before you begin: Verify that the LocalDomainServers group includes the server you plan to install the BlackBerry Enterprise
1. On a computer hosting the IBM Lotus Domino administration console, in the administration server directory, create an
IBM Lotus Domino group with the following properties:
• Name: BlackBerryAdmins
• Group type: Access Control List only
• Description: Users who can add, delete, and change settings for BlackBerry device users
• Members: LocalDomainServers, any groups or users who might administer the BlackBerry Enterprise Server
2. On the server on which you plan to install the BlackBerry Enterprise Server, replicate the group in the IBM Lotus
I've attached the guide; you can also find RIMs documentation here