Subdocumento de preenchimento de mangusto

Order.findOne({ _id: req.body.id})
    .select('-_id productOrder')
    .populate('productOrder')
    .exec(function (err, orderObj) {
      if(!err) {
        var productOrder = orderObj.productOrder;
        //products.forEach(function(elem){
            console.log("products = " + JSON.stringify(productOrder));
        //});

        console.log("REQ._ID " + req.body.id);
        res.render('store/cart', {
            title: 'MyCart',
            angularApp: 'storeApp',
            products: productOrder
        });
      }
    });