Fix Advanced Custom Field dynamic key filter for repeater entries automagically. See example 5 http://www.advancedcustomfields.com/resources/how-to/how-to-query-posts-filtered-by-custom-field-values/

acf_repeater_dynamic_where.php

<?php

/*
 * Fix Advanced Custom Field dynamic key filter for repeater entries
 * @link http://www.advancedcustomfields.com/resources/how-to/how-to-query-posts-filtered-by-custom-field-values/
 */
add_filter( 'posts_where', 'acf_repeater_dynamic_where', 10, 2 );
function acf_repeater_dynamic_where( $where, &$wp_query ){
	if( !empty( $wp_query->meta_query->queries ) ){
		$keys = wp_list_pluck( $wp_query->meta_query->queries, "key" );
		foreach( $keys as $key ){
			if( strpos( $key, '%') !== false ){
				// custom filter to replace '=' with 'LIKE' for key
				$where = str_replace("meta_key = '{$key}'", "meta_key LIKE '{$key}'", $where);
			}
		}
	}
	return $where;
}