Specify shipping countries available per level

my_pmpro_shipping_address_country_options.php

<?php
/**
 * Specify shipping countries available per level
 *
 * List of country codes: https://en.wikipedia.org/wiki/List_of_ISO_3166_country_codes
 *
 * 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/
 */
function my_pmpro_shipping_address_country_options() {
	global $pmpro_user_fields;
	
	// Bail if Shipping Address Add On isn't active
	if( ! function_exists( 'pmproship_add_user_fields' ) ) {
		return;
	}
	
	// Get pmpro_scountry field array key
	$field_exists = false;
	foreach( $pmpro_user_fields['Shipping Address'] as $scountry_key => $field ) {
		if( $field->name == 'pmpro_scountry' ) {
			$field_exists = true;
			continue;
		}
	}
	
	// Bail if pmpro_scountry field wasn't found
	if( ! $field_exists ) {
		return;
	}
	
	$level = pmpro_getLevelAtCheckout();
	
	switch ( $level->id ) {
		case 1:
			$countries = array('AF', 'AX', 'AL'); // countries to remove for level 1
			break;
		case 2:
			$countries = array('DZ', 'AS', 'AD'); // countries to remove for level 2
			break;
	}
	
	if( isset( $countries ) ) {
		my_shipping_options_remove_countries( $countries, $scountry_key );
	}

}
add_action( 'pmpro_checkout_after_billing_fields', 'my_pmpro_shipping_address_country_options', 9 );

function my_shipping_options_remove_countries( $countries, $scountry_key ) {
	global $pmpro_user_fields;
	
	foreach( $countries as $country ) {
		unset( $pmpro_user_fields['Shipping Address'][$scountry_key]->options[$country] );
	}	
}