Можете да опитате това:
db.collection.find().forEach( function (x) {
lines = x.address.split(",");
obj = {};
userAddressList = [];
lines.forEach( function (address){
addressArray = address.replace(/^\s\s*/, '').replace(/\s\s*$/, '').split(" ");
obj[addressArray[0]] = !isNaN(parseInt(addressArray[1])) ? parseInt(addressArray[1]) : addressArray[1];
});
obj.building = "";
obj.intercom = "";
userAddressList.push(obj);
x.userAddressList = userAddressList; // convert field to string
db.collection.save(x);
});