Change code to use Async Parallel

Using Async parallel

// Here mariaItem is called first and then moves onto mariaView. 
// mariaView has two callbacks happening asynchronously but they need the info from mariaItem first.

var mariaItem = function (req, res, next) {
        Item.findOne({ _id: "5099803df3f4948bd2f98391"}, function (err, result){
             req.contents = {};
             req.contents.result = result;
            next();
        });
    };

var mariaView = function (req, res, next){
    async.parallel([
        function(callback){
            User.findOne({ _id: req.contents.result.seller.sellerId}, function (err, result) {
                req.contents.seller = result;
                callback();
            });
        },
        function(callback){
            Group.find({ _id: {$in: req.contents.result.groups}}, function (err, result){
                req.contents.groups = result; 
                callback();   
            }); 
        }], function(err, something){
             res.json(req.contents);
     }); 
};  

app.get('/maria/item',
        mariaItem,
        mariaView  
        //mariaTwo,
        //mariaS,
        //mariaG
        // mariaShowIt
        );