Order post by categories id

filtre-order.php

<?php
// On tri par par ordre des termes dans la tax_query
add_action( 'pre_get_posts', 'w_filter_query' );
function w_filter_query( $q ) {
	if ( ! is_admin() && 'product' == $q->get('post_type') && is_post_type_archive( 'product' ) ) {
		$q->set( 'need_special_order', 'tq_order' );
	}
}

add_filter('posts_orderby', 'edit_posts_orderby', 100, 2);
function edit_posts_orderby( $orderby_statement, $wp_query ) {
	if ( $wp_query->get( 'need_special_order' ) && '' != $wp_query->get( 'need_special_order' ) ) {
		$tq = $wp_query->get( 'tax_query' );
		if ( ! empty( $tq[ $wp_query->get( 'need_special_order' ) ]['terms'] ) ) {
			$order = implode( ', ', $tq[ $wp_query->get( 'need_special_order' ) ]['terms'] );
			$orderby_statement = " FIELD( wpsp_term_relationships.term_taxonomy_id, {$order}) ASC, menu_order ASC ";
		}
	}
	return $orderby_statement;
}

ma-requete.php

<?php

// On filtre les termes à afficher sur la page, via pre_get_posts
add_action( 'pre_get_posts', 'w_woocommerce_posts' );
function w_woocommerce_posts( $q ) {
	if ( is_admin() ) {
		return false;
	}
	if ( ! $q->is_main_query() || ! $q->is_post_type_archive( 'product' ) || 'product' != $q->get( 'post_type' ) ) {
		return false;
	}
	
	// ici une option avec un tableau des ID de termes à afficher sur cette page
	$requiered_terms = get_option( 'options_cat_a_afficher', array() );
	
	$tq = $q->get( 'tax_query', array() );
	$tq['tq_order'] = array(
		'taxonomy' => 'product_cat',
		'terms'    => $requiered_terms,
	);
	$q->set( 'tax_query', $tq );
	$q->set( 'posts_per_page', -1 );
}