Простой способ - вы можете указать. * в начале, потому что find соответствует всему пути.
$ find . -regextype egrep -regex '.*[a-f0-9\-]{36}\.jpg$'
найти версию
$ find --version
find (GNU findutils) 4.6.0
Copyright (C) 2015 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by Eric B. Decker, James Youngman, and Kevin Dalley.
Features enabled: D_TYPE O_NOFOLLOW(enabled) LEAF_OPTIMISATION
FTS(FTS_CWDFD) CBO(level=2)