var list = [{
  name: 'Dave',
  age: 35,
  address: {
    street: "1 Acacia Road",
    town: "Bondon"
  }
},{
  name: 'Bob',
  age: 40,
  address: {
    street: "2 Sesame Street",
    town: "New York"
  }
}];

toCsv(list);

name,age,address.street,address.town
Dave,35,1 Acacia Road,Bondon
Bob,40,2 Sesame Street,New York

load('toCsv.js');

var r = db.myCollection.aggregate([{
  $match:{}
}])

print(toCsv(r.result));