my $element = {
          'check' => {
                     'field' => 'OLK_BO_BK_TYPE'
                   },
          'type' => 'case',
          'case' => [
                    {
                      'value' => '1',
                      'resultset' => 'BROKER'
                    },
                    {
                      'value' => '3',
                      'resultset' => {
                                      'field' => 'OLK_BO_BK_DESC'
                                     },
                    },
                  ]
        };

##</code><code>##

my $element = {
          'check' = 'OLK_BO_BK_TYPE',
          'type' => 'case',
          'case' => [
                    {
                      'value' => '1',
                      'resultset' => 'BROKER'
                    },
                    {
                      'value' => '3',
                      'resultset' => 'OLK_BO_BK_DESC'
                    },
                  ]
        };        

##</code><code>##

hash_walk($element);

sub hash_walk
{
  my $element = shift;
           
  if(ref($element) =~ /HASH/ )
  {    
      foreach my $key (keys %$element)
      {
          if ($key =~ /field/)
          { 
             # do something here? 
             print "found $$element{$key}\n";
          }   
          hash_walk($$element{$key});
      }
  }
  elsif (ref($element) =~ /ARRAY/)
  {
      foreach my $index (@$element)
      {
        hash_walk($index);
      }
  }  
}