Hide posts with certain category from members.

pmpro-hide-content-from-members.php

<?php
/**
 * This code allows you to filter the default blog (archive) page to hide posts with certain category ID's from members.
 * This is useful if you want to hide free content from paying members.
 * Adjust line 16 & 21 to your needs. If the user does not have a membership level, the posts page won't be filtered/changed.
 * 
 * Add the code below to your PMPro Customizations Plugin - https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 * Reference: https://developer.wordpress.org/reference/hooks/pre_get_posts/
 * www.paidmembershipspro.com
 */
 
function pmpro_exclude_categories_for_members( $query ) {
	if ( function_exists( 'pmpro_hasMembershipLevel' ) ) {
		if ( ! pmpro_hasMembershipLevel() ) {
			return $query; // You may also adjust the $query for your needs for non-members/non-access users.
		}
	}
    if ( ( $query->is_home() && $query->is_main_query() ) || ( is_search() && '' != $query->query_vars['s'] ) ) {
        $query->set( 'cat', '-2,-3,-4' ); // Category ID's to exclude for members.
    }
}
add_action( 'pre_get_posts', 'pmpro_exclude_categories_for_members' );