From ACF posts.php and api-field-groups.php, this should get you started:
$posts = get_posts(array(
'post_type' => 'acf-field-group',
'posts_per_page' => -1,
'orderby' => 'menu_order title',
'order' => 'asc',
'suppress_filters' => false, // allow WPML to modify the query
'post_status' => 'publish',
'update_post_meta_cache' => false
));