Get some properties from an object and nested object

I'd like return an object (ExpandoObject) with only the fields and nested fields received by the method.

var fieldsToGet = new List<string> { "FirstName", "Id"};

When I do this :

.Select(x => Helpers.FilteringProperties(x, fieldsToGet))

I receive an object with this two values, that's work. I receive an object with FirstName and Id

Now I'd like return some properties of the nested object :

var fieldsToGet = new List<string> { "FirstName", "Id", "Language.Name"};

I'd like receive these properties : FirstName, Id and Language.Name

The code below works but I'd like stay generic enough and be able to manage the nested.

How can I do this generic, managed the nested object ?

Thanks,

The current code :

public static object FilteringProperties(object employee, List<string> fields)
{
    if (!fields.Any())
        return employee;
    else
    {
        ExpandoObject result = new ExpandoObject();
        foreach (var field in fields)
        {
            var fieldValue = employee.GetType()
            .GetProperty(field, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance)
            .GetValue(employee, null);

            ((IDictionary<String, Object>)result).Add(field, fieldValue);
        }
        return result;
    }
}

Sample classes :

public class Employee
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }

    public Language Language { get; set; }
    public int LanguageId { get; set; }
}

public class Language
{
    public int Id { get; set; }
    public string Code { get; set; }
    public string Name { get; set; }
}