show hidden levels in special conditions

adjust_pmpro_levels_array.php

<?php
/**
 * Bring back hidden levels for those users currently having that level or they had recently.
 * $hidden_level is the id of the level to bring back.
 * $end_date_to_compare is the date to compare to determine how much time ago the user had the level.
 * 
 * Add this code to your site by following this guide - https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */
function adjusting_the_pmpro_levels_array( $levels ) {
    $current_user = wp_get_current_user();
    // fetch levels again but bringing hidden.
	$levels = pmpro_getAllLevels(true, true);
    $new_levels = array();
    // 2 is the hidden level, change the id with the one need to hide and make available for certain users.
    $hidden_level = "2";
	foreach ( $levels as $level ) {
		if($level->id === $hidden_level  ) {
            global $wpdb;
			$user_level = pmpro_getSpecificMembershipLevelForUser( $current_user->ID, $level->id );

			$has_level = ! empty( $user_level );
            //compare date to determine how much time ago the user had the level.
			$end_date_to_compare = date("Y-m-d h:m", strtotime("-1 month"));
			$had_level = $user_id = $wpdb->get_row( $wpdb->prepare( "
				SELECT membership_id 
				FROM $wpdb->pmpro_memberships_users
				WHERE user_id = %d 
				AND membership_id = %d
				AND enddate > %s",
				array( $current_user->ID, $hidden_level, $end_date_to_compare )
			) );

			if ( $has_level || $had_level ) {
				$new_levels[] = $level;
			}
		} else {
            $new_levels[] = $level;
        }
	}
	return $new_levels;
}
add_filter( 'pmpro_levels_array', 'adjusting_the_pmpro_levels_array' );