Subgroups are not showing in the client

We have an LDAP integrated installation. If I activate a group it shows to the user members but not the subgroup members.

e.g.

Group 1

member A

member B

member C

Subgroup A

Subgroup B

The members (A-C) can see the group in their client but they can’t see the members of the subgroups nor can the members of the subgroups see the main group. Is there a way in OpenFire to enable this? I tried the "Share group with additional users and selected Subgroup A-B but that does not seem to work very well.