As alternative to XML::Rules, there also is XML::Twig, which basically is the same but a little different. It requires XML::Parser as prerequisite.

If you want to see all the Xpath expressions that occur in an XML file, here's a program I use to find the structure of an XML file in absence of an XSD:

#!perl
use strict;
use XML::Twig;

my %path;

sub handle_tag {
    my( $twig )= @_;
    my $tag= $_;
    my $path= $tag->path( );
    print $path, "\n"
        unless $path{ $path }++;
    $tag->purge;
};

  my $twig=XML::Twig->new(   
    twig_handlers => 
      {
           _all_ => \&handle_tag,
      },
);

$twig->parsefile( $ARGV[0] );

print "\n-------\n\n";

for my $k (sort keys %path) {
    print "$k\t$path{ $k }\n";
};
[download]

.. i'm so slow in responding...
This is my best with your data (surely can be improved): UPDATE: the code was broken, updated...

my $t= XML::Twig->new( pretty_print => 'indented',
                    twig_handlers => {
                          'product'=>sub{  
                                              my @pname = $_[1]->get_x
+path('name');
                                              my @pids = $_[1]->get_xp
+ath('product_id');
                                              
                                              print $pids[0]->text," -
+ ",$pname[0]->text,"\n";
                                              my %h;
                                              
                                              my @ids = $_[1]->get_xpa
+th('attributes/attribute/group/id');
                                              my @names = $_[1]->get_x
+path('attributes/attribute/group/name');
                                              @h{map {$_->text} @ids }
+ = map {$_->text} @names ;


                                              my @vids = $_[1]->get_xp
+ath('attributes/attribute/value/id');
                                              my @values = $_[1]->get_
+xpath('attributes/attribute/value/value');
                                              @h{map {$_->text} @vids 
+} = map {$_->text} @values ;

                                              print map {"\t$_ - $h{$_
+}\n"} keys %h;
                                              print "\n\n";
                                             

                          }
                    }
);
$t->parse($xml);


####OUTPUT
ABC123 - My product
         - 12.1998
        1561 - Lõngd (i mm)
        1507 - Engines
        1498 - Year model
        12033 - Vehicle equipment
        12019 - Maybe
        1518 - Year model (to)
        301 - Generator


XYZ789 - My product
         - 12.1992
        1507 - Engines
        1498 - Year model
        1518 - Year model (to)
        301 - Generator
[download]

HtH
L*


There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

Nice.

In case you, or the reader, don't know: in handlers $_ is aliased to $_[1], so you can write ,$_->get_xpath(...) instead of $_[1]->get_xpath(...). Beyond saving 3 characters each time, I am used to $_ meaning "the current element" within a handler, and I find it easier to read.

instead of XML::Simple use XML::Rules, see more about xml rules

Then there is XML::Twig Quick Reference and XML::LibXML

HTML::TreeBuilder::XPath or XML::LibXML with tools like xpather.pl/htmltreexpather.pl which can give you paths to start with, and all the links here Re: Retrieve select information from HTML, they're examples(for tree-xpath and others)/walkthroughs/tutorials ...

To use XML::LibXML on large files, use the pull parser XML::LibXML::Reader. For example, the following script
Read more... (1325 Bytes)

produces the following output:

ABC123
        group [ 1507 : Engines ]
        value [ 301 : Generator ]
        group [ 1561 : Längd (i mm) ]
        value [  : 2625 ]
        group [ 1498 : Year model ]
        value [  : 01.1994 ]
        group [ 1518 : Year model (to) ]
        value [  : 12.1998 ]
        group [ 12033 : Vehicle equipment ]
        value [ 12019 : Maybe ]

XYZ789
        group [ 1507 : Engines ]
        value [ 301 : Generator ]
        group [ 1498 : Year model ]
        value [  : 01.1985 ]
        group [ 1518 : Year model (to) ]
        value [  : 12.1992 ]
[download]

لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

I may be a tiny bit biased...