#!/usr/bin/perl

use strict;
use warnings;
use HTML::TokeParser::Simple;

my $html = do{local $/; <DATA>};

my $p = HTML::TokeParser::Simple->new(\$html)
 or die "can't parse string: $!\n";

while (my $t = $p->get_token){
  last if $t->is_end_tag('span');
}

my ($match, @li_stack);

while (my $t = $p->get_token){
  if ($t->is_start_tag('li')){
    push @li_stack, 'li';
  }
  if ($t->is_end_tag('li')){
    if (@li_stack){
      pop @li_stack;
    }
    else{
      last;
    }
  }
  $match .= $t->as_is;
}

print "$match\n";

__DATA__
<li><span class="title">Title</span><ul><li>one</li><li>two</li></ul> MATCH HERE </li>

##</code><code>##

<ul><li>one</li><li>two</li> MATCH HERE