Filotro de busca WordPress com taxonomys

filter_search_WordPress_per_taxonomy.php

<?php
    function filter_search( $query )  {
        if ( !is_admin() && $query->is_main_query() && $query->is_search ) {
            $tax_query = array(
                            array(
			                    'taxonomy' => 'frutas',
			                    'field' => 'slug',
			                    'terms' => 'laranja'
		                    ),
		                    array(
			                    'taxonomy' => 'frutas',
			                    'field' => 'slug',
			                    'terms' => 'maca'
	                        ),
		                    'relation' => 'AND'
                        );
            $query->set( 'tax_query', $tax_query );
        }
    }
    add_action ('pre_get_posts', 'filter_search' );