Show number of spots available for a membership level Paid Memberships Pro.

pmpro_show_spots_available.php

<?php
/**
 * This will show '0/X spots available.' on membership level description if a limit is set from (https://www.paidmembershipspro.com/limit-number-members-membership-level/)
 * Add this code to your PMPro Customizations Plugin - https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 * For help, post a support thread on www.paidmembershipspro.com
 */
 
function pmpro_show_spots_available( $description, $level ) {
	global $wpdb;

	$level_id = intval( $level->id );

	//get the maximum number of members allowed in this level
	$limit = get_option( 'pmpro_limit_' . $level_id );

	// if the limit is not set, just return the default description for that level.
	if( empty( $limit ) ){
		return $description;
	}
	
	//get the count of members in this level
	$sql = "SELECT COUNT(*)
            FROM {$wpdb->pmpro_memberships_users}
            WHERE `status` = 'active' AND `membership_id` = ". esc_sql($level_id);
	$member_count = $wpdb->get_var($sql);

	$description .= $member_count . '/' . $limit;
	$description .= ' spots available.';

	return $description;

}
add_filter( 'pmpro_level_description', 'pmpro_show_spots_available', 10, 2 );