/usr/share/fusiondirectory/plugins/ is in fusiondirectory-plugin-samba 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/samba/
/usr/share/fusiondirectory/plugins/admin/samba/class_sambaDomain.inc
/usr/share/fusiondirectory/plugins/admin/samba/class_sambaDomainManagement.inc
/usr/share/fusiondirectory/plugins/admin/samba/main.inc
/usr/share/fusiondirectory/plugins/admin/systems/
/usr/share/fusiondirectory/plugins/admin/systems/samba/
/usr/share/fusiondirectory/plugins/admin/systems/samba/class_winstationGeneric.inc
/usr/share/fusiondirectory/plugins/config/
/usr/share/fusiondirectory/plugins/config/samba/
/usr/share/fusiondirectory/plugins/config/samba/class_sambaPluginConfig.inc
/usr/share/fusiondirectory/plugins/personal/
/usr/share/fusiondirectory/plugins/personal/samba/
/usr/share/fusiondirectory/plugins/personal/samba/class_sambaAccount.inc
/usr/share/fusiondirectory/plugins/personal/samba/class_sambaLogonHours.inc
/usr/share/fusiondirectory/plugins/personal/samba/class_sambaMungedDial.inc
/usr/share/fusiondirectory/plugins/personal/samba/main.inc
/usr/share/fusiondirectory/plugins/personal/samba/sambaLogonHours.tpl