/usr/lib/xen-common/bin/xend-domain-config-path-strip is in xen-utils-common 4.4.0-0ubuntu5.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 | #!/bin/sh -e
CONFDIR=/var/lib/xend/domains
if [ $(id -u) -ne 0 ]; then
	echo "Must be called as root" >&2
	exit 1
fi
for CFG in $(find $CONFDIR -type f); do
	awk '
		/\(loader/ && /\/usr\/lib\/xen-/{
			sub(/\/usr\/lib\/xen-.*\/boot\//, "")
			print
			next
		}
		/\(device_model/ && /\/usr\/lib\/xen-/{
			sub(/\/usr\/lib\/xen-.*\/bin\//, "")
			print
			next
		}
		{
			print
		}
	' $CFG >/tmp/xend-domain.$$
	if ! diff -q $CFG /tmp/xend-domain.$$ >/dev/null; then
		echo "Updating $(basename $(dirname $CFG))"
		cat /tmp/xend-domain.$$ >$CFG
	fi
	rm /tmp/xend-domain.$$
done
 |