Feeds Importer Filters
You can create a new module and implement the hook_feeds_presave() function like the following example:

function hook_feeds_presave(FeedsSource $source, $entity, $item) {
  // create your filter conditions here
  if ($entity-&gt;feeds_item-&gt;entity_type == 'node') {
    // Skip saving this entity.
    $entity-&gt;feeds_item-&gt;skip = TRUE;
  }
}