"result": {
        "parameters": {
            "age": {
                "amount": 10,
                "unit": "year"
            }
        },

public class Age
    {
        public int amount { get; set; }
        public string unit { get; set; }
    }
    public class RequestParameter
    {
        public Age age { get; set; }
    }
    public class RequestBody
    {
        public RequestParameter parameters { get; set; }
    }
    [HttpPost]
    public ActionResult GetValue(RequestBody result)
    {
        var age = result.parameters.age.amount;
        ...