There isn’t any good way to query posts based on a repeater field. Basically what you need to do is a MySQL query using $wpdb to get a list of post IDs that have the values you want and then use that list with the “post__in” argument for WP_Query. Doing the MySQL query is covered here: http://www.advancedcustomfields.com/resources/querying-the-database-for-repeater-sub-field-values/
