/usr/lib/libreoffice/share/registry/oo-ad-ldap.xcd.sample is in libreoffice-common 1:3.5.7-0ubuntu13.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libreoffice/share/registry/../../../../share/doc/libreoffice-common/examples/oo-ad-ldap.xcd.sample