Hi,
I have OpenVPN authenticating against my OpenLDAP server. It's not happening as I would like it to, but this may get you started:
From your jpegs the distinguishedName of your users is in the format: uid=name,ou=Users,dc=hn,dc=local
So...your BaseDN should be: ou=Users,dc=hn,dc=local
Level: One Level
Set your Authentication Container to the same: ou=Users,dc=hn,dc=local
User naming attribute should be: uid (as that is what you use!)
Group naming attribute and Group member attribute make little difference at this point.
This will allow ANYONE in your ou=Users tree to log in. Which may, or more likley, may not, be what you want. And this is the problem I'm having.
I have a user with the DN of: uid=fred,ou=people,dc=example,dc=com
Setting the VPN up as above the he can connect sucessfully and the logs say:
openvpn: : Now Searching for fred in directory.
openvpn: : Now Searching in server MyLDAP, container ou=people,dc=example,dc=com with filter (uid=fred).
Logged in successfully as fred via LDAP server MyLDAP with DN = uid=fred,ou=people,dc=example,dc=com.
openvpn: user fred authenticated
I'm guessing that, like me, you want only users in your cn=pmb_vpn group to have access. From your images I can't see if your vpn group is static or dynamic. That said, I can't get either to work. I think that dynamic groups are a no-no on account of how they are searched, but I have a static group and it still doesn't work. The static group (cn=vpn,ou=groups,dc=example,dc=com) has the following members who may use the VPN:
member: uid=fred,ou=people,dc=example,dc=com
member: uid=joe,ou=people,dc=example,dc=com
etc..
I set my Authentication Container to: cn=vpn,ou=groups,dc=example,dc=com
User naming attribute remains: uid
Group naming attribute: cn
Group member attribute: member
And I try the VPN with the user fred...but I get the following log:
openvpn: : Now Searching for fred in directory.
openvpn: : Now Searching in server MyLDAP, container cn=vpn,ou=groups,dc=example,dc=com with filter (uid=fred).
openvpn: : ERROR! Either LDAP search failed, or multiple users were found.
openvpn: user fred could not authenticate.
And the VPN doesn't authenticate

Ideally I need it to filter the ou=people branch with: "(&(uid=fred)(vpnUser=true))" as I have a bespoke attribute vpnUser which is either true of false for each user (that is how the dynamic vpn group was created).