Set Custom Redirection After Registration

/**

 * Send the user to a custom page after they have registered.

 *

 * @param   array[] $fields

 * @return  array[] $fields

 */

function en_set_custom_redirection_after_registration( $fields ) {

    if ( ! isset( $_GET[ 'redirect_to' ] ) ) {

        $fields[ 'redirect_to' ] = array(

            'type' => 'hidden', 

            'priority' => 2,

            'value' => 'http://your-custom-url.com/' // This should be the URL you want the user to be redirected to.

        );

    }    

    return $fields;

}

add_filter( 'charitable_user_registration_fields', 'en_set_custom_redirection_after_registration' );