## is the .+ necessary after bb?
if( $hit =~ /%(?:ff|jj|bb)/ )
## alternate version
if( $hit =~ /%[fjb]\1\b/ )

##</code><code>##

use File::Find::Rule;

my @files = find(
  file =>
  grep => qr/%[fjb]\1\b/,
  in   => '/disk1/disk2'
);