Change to change PayPal order description to "billing_name - level_name".

my_pmpro_paypal_level_description.php

<?php

/**
 * Change PayPal order description to "billing_name - level_name".
 */
function my_pmpro_paypal_level_description( $description, $level_name, $order, $site_name ) {
	
	// Get name from billing address.
	$name = $order->billing->name;
	$description = "{$name} - {$level_name}";
	
	return $description;
}
add_filter( 'pmpro_paypal_level_description', 'my_pmpro_paypal_level_description', 10, 4 );