my_cpt_pmpro_member_homepage_id.php

<?php
/**
 * Set the member homepage for members of Level 3 to the post ID 232.
 *
 * 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_cpt_pmpro_member_homepage_id( $member_homepage_id, $level_id ) {
	// Only filter for Level 3.
	if ( $level_id === '3' ) {
		// Redirect to the post ID 232.
		$member_homepage_id = '232';	
	}
	return $member_homepage_id;
}
add_filter( 'pmpro_member_homepage_id', 'my_cpt_pmpro_member_homepage_id', 10, 2 );