Вот код. Вы можете изменить $ post_type и $ custom_fields в соответствии с вашими потребностями.
function extend_admin_search( $query ) {
// Extend search for document post type
$post_type = 'document';
// Custom fields to search for
/* $custom_fields = array(
"_file_name",
); */
if( ! is_admin() )
return;
if ( $query->query['post_type'] != $post_type )
return;
$search_term = $query->query_vars['s'];
// Set to empty, otherwise it won't find anything
$query->query_vars['s'] = '';
/* if ( $search_term != '' ) {
$meta_query = array( 'relation' => 'OR' );
foreach( $custom_fields as $custom_field ) {
array_push( $meta_query, array(
'key' => $custom_field,
'value' => $search_term,
'compare' => 'LIKE'
));
}
$query->set( 'meta_query', $meta_query );
}; */
$query->set( 's', $search_term );
}
add_action( 'pre_get_posts', 'extend_admin_search' );