Please note that your code as submitted does not work -- there is no test1.xml. I rewrote it to use <DATA>.

The main problem is that cloneNode only makes a shallow copy; in fact you can still use the node $dead after it is unbound and it still contains all the child info. Here is my rewritten program:

#!/usr/bin/perl -w

use strict;
use XML::LibXML;

my $parser = XML::LibXML->new();
my $doc = $parser->parse_string(join "", <DATA>);

# copy the node, then delete it
my $from_path = q{/category/subcategory/product[product_id = "800.55.0
+1"]};
my @from_nodes = $doc->findnodes( $from_path);
my $dead = $from_nodes[0];  # Assume there can be only one
$dead->unbindNode;

# paste the node to a new location
my $to_path = q{/category/subcategory[@name = "Grand Arabica"]};
my @to_nodes = $doc->findnodes( $to_path);
my $paste = $to_nodes[0];  # Assume there can be only one
my $lastnode = $paste->lastChild();
$paste->insertAfter( $dead, $lastnode);

print $doc->toString([0]);
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