It's not clear to me what you are trying to achieve here (assigning a hash ref to an array doesn't make sense), but the following may help:

use warnings;
use strict;
use XML::Twig;
use Data::Dump::Streamer;

my $xml = <<XML;
<config>
  <computer id="one" type="mac" os="XP" >
        <lease true="yes" />
        <extra_device value="scanner"/>
        <entertainment>
           <game id="tekken" company="nameco" />
             <platform value="pc only" />
             <year value="1980" />
           <game id="tekken 2" company="ninja" />
             <platform value="pc and mac" />
             <year value="1989" />
        </entertainment>
  </computer>
  <computer id="two" type="pc" os="NT" >
        <lease true="no" />
        <work>
            <software value="final" />
        </work>
  </computer>

  <company_name id="nameco" origin="ca" type="violence" production="ye
+s">
        <sponsor name="sony" percentage="30" active="true"/>
             <sponsorlist>
                  <sponsor id="sony1" active="false"/>
                  <sponsor id="sony2" active="true"/>
                  <sponsor id="sony3" active="false"/>
             </sponsorlist>
  </company_name>
  <company_name id="ninja" origin="ny" type="extreme violence" product
+ion="yes">
        <sponsor name="WB" percentage="20" active="true"/>
             <sponsorlist>
                  <sponsor id="WB1" active="false"/>
             </sponsorlist>
  </company_name>
</config>
XML

my $yahoo = 'one';

my @ones;
my $twig   = XML::Twig->new (
    pretty_print => 'indented',
    twig_roots => {
        computer => sub {oneHandler (\@ones, $yahoo, @_);}
    }
);

$twig->parse ($xml);

Dump (\@ones);

sub oneHandler {
    my ($ones, $yabal, $twig, $elt) = @_;

    return unless $elt->att ('id') eq $yabal;

    for my $child ($elt->children ()) {
        my %atts = %{$child->atts ()};

        next unless %atts;
        push @$ones, \%atts;
    }
}
[download]

Prints:

$ARRAY1 = [
            { true => 'yes' },
            { value => 'scanner' }
          ];
[download]