Solved! I use switch_to_blog();
global $wpdb;
$result_sql .= "
SELECT ID AS id
";
switch_to_blog(9);
foreach($wpdb->get_results($result_sql, OBJECT) as $rss) {
$map = get_post_meta($rss->id, 'gmap', true);
$map["lat"];
$map["lng"];
} restore_current_blog();