I have two mongoose schema

var mongoose = require('mongoose');

var Schema = mongoose.Schema;

var itemSchema = new Schema({

    name: {type: String, required: true, max: 25, trim: true},
    price: {type: Number, required: true, trim: true, default: 0},
    tax: {
        type: Schema.Types.ObjectId,
        ref: "Store"
    }
});

module.exports = mongoose.model('Item', itemSchema);

The second Schema

var mongoose = require('mongoose');

var Schema = mongoose.Schema;

var storeSchema = new Schema({
    name: {type: String, required: true, trim: true},
    taxes: [
        {
            name: String,
            rate: Number
        }
    ]
});

module.exports = mongoose.model('Store', storeSchema);

What I want to do is populate the itemSchema tax object with the storeSchema taxes array of object. every time I pushed a new tax object to the taxes array mongoose created an ObjectId. I stored that ObjectId in my itemSchema Tax. I want to use that _id to retrieve the store taxes that matches the itemSchema _id.

I have tried this so far, but I get no in the tax attribute.

Item.find().populate("tax", "taxes").exec(function (err, docs) {
        if (err) return console.error(err);
        console.log(items);
    });