anchor.diff:      var selectedKind = $('.selectKind').val();
       var selectedNeighborhood = $('.selectNeighborhoods').val();
   
  -    function groupList(selKind, selNeighborhood)
  +    function groupList(selKind, selNeighborhood) {
  +      $('tr').show();
  +      if (selKind != 'all' && selNeighborhood != 'all') {
  +        $('tr').not('.' + selectedNeighborhood).hide();
  +        $('tr').not('.' + selectKind).hide();
  +      } else if (selKind == 'all' && selNeighborhood != 'all') {
  +        $('tr').not('.' + selectedNeighborhood).hide();
  +      } else if (selNeighborhood == 'all' && selKind != 'all') {
  +        $('tr').not('.' + selectKind).hide();
  +      }
  +    }
   
       $('.selectKind').change(function(){
  -      selectKind = $(this).val();
  -      $('table').show()
  -      if (selectKind != 'all' && selectedNeighborhood != 'all') {
  -        $('tr').not('.' + selectedNeighborhood, '.' + selectKind).hide()
  -      }
  -      else if (selectKind == 'all') {
  -
  -      }
  +      selectedKind = $(this).val();
  +      groupList(selectedKind, selectedNeighborhood);
       });
   
  -    $('.selNeighborhoods').change(function(){
  +    $('.selectNeighborhoods').change(function(){
         selectedNeighborhood = $(this).val();
  -      $('table').show()
  -      $('tr').not('.' + selectedNeighborhood, '.' + selectKind).hide()
  +      groupList(selectedKind, selectedNeighborhood);
       });
     });
   </script>
  
positive.code: 
    <tbody>
      <% @groups.each do |group| %>
        <tr class='<%= group.neighborhood %> <%= group.kind %>'>
          <td><%= group.id %></td>
          <td><%= group.neighborhood.title %></td>
          <td><%= group.name %></td>
  
negative.code: <select class="selectNeighborhoods">
    <option selected="selected" value="all"> All </option>
    <%= @neighborhoods.each do |neighborhood| %>
      <option value=<%= neighborhood.id %>><%= neighborhood.title %></option>
    <% end %>
  </select>
  
  