/usr/share/fusiondirectory/plugins/ is in fusiondirectory-plugin-kolab 1.0.8.8-3ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/fusiondirectory/plugins/admin/
/usr/share/fusiondirectory/plugins/admin/ogroups/
/usr/share/fusiondirectory/plugins/admin/ogroups/kolab/
/usr/share/fusiondirectory/plugins/admin/ogroups/kolab/class_mailogroup.inc
/usr/share/fusiondirectory/plugins/admin/ogroups/kolab/mail.tpl
/usr/share/fusiondirectory/plugins/admin/ogroups/kolab/paste_mail.tpl
/usr/share/fusiondirectory/plugins/admin/systems/
/usr/share/fusiondirectory/plugins/admin/systems/services/
/usr/share/fusiondirectory/plugins/admin/systems/services/kolab/
/usr/share/fusiondirectory/plugins/admin/systems/services/kolab/class_serviceKolab.inc
/usr/share/fusiondirectory/plugins/personal/
/usr/share/fusiondirectory/plugins/personal/kolab/
/usr/share/fusiondirectory/plugins/personal/kolab/class_kolabAccount.inc
/usr/share/fusiondirectory/plugins/personal/kolab/main.inc
/usr/share/fusiondirectory/plugins/personal/mail/
/usr/share/fusiondirectory/plugins/personal/mail/kolab/
/usr/share/fusiondirectory/plugins/personal/mail/kolab/class_mail-methods-kolab.inc
/usr/share/fusiondirectory/plugins/personal/mail/kolab/class_mail-methods-kolab22.inc