search.php

<?php

function custom_search_filter( $query ) {
    global $wpdb;
    if ( $query->is_search() && ! is_admin() ) {
        $search_query = get_search_query();
        $results = $wpdb->get_results(
            $wpdb->prepare(
                "SELECT p.ID, p.post_title, m.meta_value
                FROM {$wpdb->prefix}posts AS p
                INNER JOIN {$wpdb->prefix}postmeta AS m
                    ON p.ID = m.post_id
                WHERE p.post_type = %s
                    AND p.post_status = 'publish'
                    AND m.meta_key = '_short_description'
                    AND m.meta_value LIKE %s",
                'product', // Substitua 'product' pelo nome do seu tipo de post personalizado
                '%' . $wpdb->esc_like( $search_query ) . '%' // Use a consulta de pesquisa padrão para obter o termo de pesquisa
            )
        );
        $post_ids = array();
        foreach ( $results as $result ) {
            $post_ids[] = $result->ID;
        }
        $query->set( 'post__in', $post_ids );
    }
}
add_action( 'pre_get_posts', 'custom_search_filter' );