$hashref->{'globalkey'}->{'key2'}->{'key3'}->{'key4'}='ARRAY VALUE';
$hashref->{'globalkey'}->{'key2'}->{'key3'}->{'key4'}->{'key5'}='ARRAY VALUE';
$hashref->{'globalkey'}->{'key2'}->{'key3'}->{'key4'}->{'key5'}->{'any arbitrary number of keys'}='ARRAY VALUE';

use Data::Dumper;
print Dumper($hashref);
__END__
$VAR1 = {
          'globalkey' => {
                           'key2' => {
                                       'key3' => {
                                                   'key4' => 'ARRAY VALUE'
                                                 }
                                     }
                         }
        };