my_pmpro_change_text_example.php

<?php
/**
 * This recipe replaces text strings in the content filter.
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

add_filter( 'gettext', 'change_my_text_example', 20, 3 );
/**
 * @link http://codex.wordpress.org/Plugin_API/Filter_Reference/gettext
 */
function change_my_text_example( $translated_text, $text, $domain ) {  

        switch ( $translated_text ) {

            case 'You have selected the %s membership level.' :

                $translated_text = __( '', 'paid-memberships-pro' );
                break;
        }

    return $translated_text;
}