Remove the restricted messages shown on the /forums/ archive in BuddyBoss.

my_pmpro_remove_no_access_message_from_bbp_is_forum_archive.php

<?php
/**
 * Remove the restricted messages shown on the /forums/ archive in BuddyBoss.
 * BuddyBoss is running the /forums/ page content through the the_content filter, which detects protected forums within the loop.
 */
function my_pmpro_remove_no_access_message_from_bbp_is_forum_archive( $text ) {
	// Check if we are on the homepage.
	if ( function_exists( 'bbp_is_forum_archive' ) && bbp_is_forum_archive() ) {
		// Return an empty string.
		return '';
	}

	// Otherwise, return the default no access message.
	return $text;
}
add_filter( 'pmpro_no_access_message_html', 'my_pmpro_remove_no_access_message_from_bbp_is_forum_archive', 10, 1 );