I did and this is why I'm posting to help others.
Originally Posted by juanschwartz
Scenario : I want my users to connect to OpenVPN only if they are member of a group (which is a "distribution list" in the Zimbra world). On this example, my distribution list is called "vpnusers".
1. Create a distribution list and check the option "Dynamic Group".
The Dynamic Group option is the key here.
This will create a new branch in cn=groups,dc=yourserver,dc=com
In our case: cn=vpnusers,cn=groups,dc=yourserver,dc=com
Without this option, your distribution list will only appear in : ou=people,dc=yourserver,dc=com
2. Setup the Authorization section of your OpenVPN LDAP configuration
# Base DN
# User Search Filter
# Require Group Membership