Filter EDD Hide Download's redirect when "Disable direct access to this download" is enabled, on a per download level

gistfile1.php

<?php

function sumobi_custom_edd_hide_download_redirect( $url ) {
  // download has ID of 17
	if ( '17' == get_the_ID() ) {
		$url = 'http://easydigitaldownloads.com'; // redirect user to another external URL
	}
	
	// download has ID of 15
	if( '15' == get_the_ID() ) {
		$url = get_permalink( '8' ); // redirect to another download which has an ID of 8
	}
	
	// return our new URL
	return $url;
}
add_filter( 'edd_hide_download_redirect', 'sumobi_custom_edd_hide_download_redirect' );