functions.php

gistfile1.txt

<?php
function restrict_search_to_specific_post_type($query) {
    // Check if query is a search, is on the frontend, and is on the 'product' post type archive
    if ($query->is_search && !is_admin() && is_post_type_archive('product')) {
        $query->set('post_type', 'product');
    }
    return $query;
}
add_action('pre_get_posts', 'restrict_search_to_specific_post_type');