test.pl

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
use XML::SAX::ParserFactory;
use XML::SAX::PurePerl;

my $path=1;
my $path_text='';
my $prev_tag;
my $prev_node;
my $characters;
my @firstnames;

my $factory = new XML::SAX::ParserFactory;

my $handler = new XML::SAX::PurePerl;

my $parser = $factory->parser(
              Handler => $handler,
              Methods => {
                  characters => sub {
                      $characters = shift->{Data};
                  },
                  start_element => sub {
                      if(  shift->{LocalName} eq 'ul' ){
                          $path +=1;
                          $path_text.='/' . $characters;
                      }
                  },
                  end_element => sub {
                      my $el=shift;
                      push @firstnames, ' / ' x $path  . $characters if ($el->{LocalName} eq 'li');
                      if ($el->{LocalName} eq 'ul'){
                        $path -= 1;
                      }
                  }
              }
          );

$parser->parse_uri("3.html");
print Dumper \@firstnames;