#!/usr/bin/perl
use strict; use warnings; use autodie;
use XML::LibXML;
use Data::Dumper;
my @Docs = (
<<EOXML,
<root>
        <part>
            <sect>
               <header>
                   This is a design XZY document for Project
                </header>
            </sect>
         </part>
     </root>
EOXML

<<EOXML
  <root>
       <para>This is a design XZY document for Project</para>
       <part>
          <sect>
            <header>
                This is some header
             </header>
          </sect>
        </part>
      </root>
EOXML
);

for (my $idx=0; $idx<@Docs; ++$idx) {
    my $XML = $Docs[$idx];
    print "----------- SEARCHING DOCUMENT $idx ---------\n";
    my $dom = XML::LibXML->load_xml( string=> $XML );

    DOCSEARCH:
    for my $search ('/root/part/sect/header', '/root/para') {
        print "----- searching: $search\n";
        my $nodeset = $dom->find($search);

        foreach my $node($nodeset -> get_nodelist) {
            $node -> string_value;
            if ($node =~ m/design/i) {
                my $design= $node;
                print $design, "\n";
                last DOCSEARCH;
            }
        }
    }
}

##</code><code>##

$ perl 1041480.pl
----------- SEARCHING DOCUMENT 0 ---------
----- searching: /root/part/sect/header
<header>
                   This is a design XZY document for Project
                </header>
----------- SEARCHING DOCUMENT 1 ---------
----- searching: /root/part/sect/header
----- searching: /root/para
<para>This is a design XZY document for Project</para>