functions.php

<?php

/**
 * Modify search query to ignore the search term in HTML comments.
 *
 * @param string   $where The WHERE clause of the query.
 * @param WP_Query $query The WP_Query instance (passed by reference).
 *
 * @return string The modified WHERE clause.
 */
function bp_update_search_query( $where, $query ) {
    if ( ! is_search() || ! $query->is_main_query() ) {
        return $where;
    }
 
    global $wpdb;
    $search_query = get_search_query();
    $search_query = $wpdb->esc_like( $search_query );
 
    $where .= " AND {$wpdb->posts}.post_content NOT REGEXP '<!--.*$search_query.*-->' ";
 
    return $where;
}
add_filter( 'posts_where', 'bp_update_search_query', 10, 2 );