for my $scene ( $doc->findnodes('/PLAY/SCENE') ) {
     ITEM: for my $item ( $scene->findnodes('SPEECH') ) {
          my $speaker = $item->findvalue('SPEAKER');
          next ITEM unless $speaker eq $searchterm;
          push @{$act{$scene}}, [ map { $_->to_literal } $item->findnodes('LINE') ];
     }
}

##</code><code>##

for my $scene ( keys %act ) {
     print "SCENE $scene:\n";
     print "$searchterm:\n", join "\n", @$_ for @{$act{$scene}};
}