$ md tmp3

$ md tmp3\a

$ md tmp3\a\a

$ md tmp3\a\b

$ md tmp3\a\c

$ md tmp3\a\d

$ md tmp3\b\a

$ md tmp3\b\b

$ touch tmp3\a\b\f.pl

$ touch tmp3\a\c\f.pl

$ touch tmp3\b\b\f.pl

$ findrule tmp3 -file ( *.pl )
tmp3/a/b/f.pl
tmp3/a/c/f.pl
tmp3/b/b/f.pl

$ perl -MFile::Find::Rule -le " print for File::Find::Rule-> file( q(*.pl) )->in( q(tmp3) ); "
tmp3/a/b/f.pl
tmp3/a/c/f.pl
tmp3/b/b/f.pl

$ perl -MFile::Glob=:glob -le " while(@ARGV){ print for glob shift } " "tmp3/*pl" "tmp3/*/*pl" "tmp3/*/*/*pl"
tmp3/a/b/f.pl
tmp3/a/c/f.pl
tmp3/b/b/f.pl