my $h={ j=>{b=>"some value meaningful to another part of code"}};

##</code><code>##

return $h->{$l_id}->{$letter_code}
  if (defined $h->{$l_id}->{$letter_code});

##</code><code>##

my $h = {j=>{b=>{c=>"some other meaningful value"}}};

##</code><code>##

my $h = {j=>{b=>{c=>1}}};