$products = wc_get_products(array(
  'category'                              => array($brand_slug),
  'status'                                => 'publish',
  'limit'                                 => 20,
  'orderby'                               => 'date',
  'order'                                 => 'DESC',
  'return'                                => 'objects'
  'query'                                 => array(
    'title'                               => $title // Something like this
  )
));