Redirect BuddyPress registration to the PMPro levels page.

my_redirect_buddypress_registration_to_pmpro_levels.php

<?php
/**
 * Redirect BuddyPress registration to the PMPro levels page.
 * Add this code into a Code Snippet or custom plugin.
 * https://www.paidmembershipspro.com/how-to-add-code-to-wordpress/
 * Note that this gist will redirect users to the level pages.
 * You can adjust it to link to checkout for a specific level
 * or, if you have only one level, adjust it to link to the
 * checkout page, which will default to the first available level.
 */
function my_redirect_buddypress_registration_to_pmpro_levels() {
	global $post, $pmpro_pages;
	
	//If BP or PMPro are not active, ignore
	if( !function_exists( 'bp_is_register_page' ) || !function_exists( 'pmpro_url' ) ) {
		return;
	}

	$bp_pages = get_option( 'bp-pages' );
	
	if( bp_is_register_page() && $post->ID != $pmpro_pages['levels'] )
	{
		$url = pmpro_url("levels");
		wp_redirect($url);
		exit;
	}
}
add_action( 'template_redirect', 'my_redirect_buddypress_registration_to_pmpro_levels', 75 );