如何拉出Mongodb中的嵌套对象？

{
   "_id": ObjectId("610ad6d2e82aaf47c8d4e982"),
   "name": "John Doe",
   "age": 30,
   "address": {
      "street": "123 Main St",
      "city": "New York",
      "country": "USA"
   }
}

db.users.find({}, {"address.city": 1})

db.users.find({}, {"address": 1})

{
   "_id": ObjectId("610ad6d2e82aaf47c8d4e982"),
   "name": "John Doe",
   "age": 30,
   "orders": [
      {
         "productId": "p1",
         "quantity": 2
      },
      {
         "productId": "p2",
         "quantity": 1
      }
   ]
}

db.users.find({}, {"orders.0.productId": 1})