{
   "_id":"23456",
   "type":"address",
   "attributes":{
      "name":"San",
      "address":[
         {
            "name":"address1",
            "street":"1430 Del santra, SA",
            "city":"NY"
         },
         {
            "name":"address2",
            "city":"NY"
         }
      ]
   }
}

MongoUrl conString = new MongoUrl("mongodb://localhost:27017/");

IMongoClient dbConnect = new MongoClient(conString);
IMongoDatabase _dbMongo = dbConnect.GetDatabase("ApplicationDB");

ConventionPack _conventions = new ConventionPack();
_conventions.Add(new LowerCaseElementNameConvention());
ConventionRegistry.Register("lowercaseconvention", _conventions, t => true);
_conventions.Add(new IgnoreExtraElementsConvention(true));
ConventionRegistry.Register("IgnoreExtraElements", _conventions, t => true);

try
{
	var result = Task.Run( () => _dbMongo.GetCollection<AddressDetails>("simplecollection").Find(x => x.Type == "address" && x.Attributes.Name == "San").FirstOrDefaultAsync());
	result.Wait();
}
catch (MongoException ex)
{
	Console.WriteLine($"{ex.Message}");
}

public class AddressDetails
{
	public string Id { get; set; }
	public Attributes Attributes { get; private set; }
	public string Type { get; private set; }

public AddressDetails(string id, Attributes attributes, string type)
{
	Id = id;
	Attributes = attributes;
	Type = type;
}

public class Attributes
{
	public string Name { get; private set; }
	public List<Address> Address { get; private set; }
	public Attributes(string name, List<Address> address)
	{
		Name = name;
		Address = address;
	}
}

public class Address
{
	public string Name { get; private set; }
	public string Street { get; private set; }
	public string City { get; private set; }
	public Address(string name, string street, string city)
	{
		Name = name;
		Street = street;
		City = city;
	}
}