This code shows how to specify a navigation path in the JsonProperty attribute. It will traverse the JSON node and obtain the desired value to according to the path. Example [JsonProperty(parent/child)] will map to the value "a" from the JSON { "parent":{ "child": "a"} }. http://stackoverflow.com/questions/35628318/deserialize-nested-json-to-a-f…

Program.cs

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Linq;
using System.Reflection;

namespace ConsoleApplication1
{
    class Program
    {
        /// <summary>
        /// This code shows how to specify a navigation path in the JsonProperty attribute.
        /// It will traverse the JSON node and obtain the desired value to according to the path.
        /// Example
        /// [JsonProperty(parent/child)] will map to the value "a" from the JSON { "parent":{ "child": "a"} }.
        /// </summary>
        /// <param name="args"></param>
        static void Main(string[] args)
        {
            string s = @"
{
	""id"": 100,
	""fields"":{
		""issuetype"": {
			""name"": ""I am a Jira issue""
		}
	}
}";

            var settings = new JsonSerializerSettings();
            settings.Converters.Add(new ConventionBasedConverter());
            var o = JsonConvert.DeserializeObject<JiraIssue>(s, settings);
            Console.WriteLine("Id: " + o.Id);
            Console.WriteLine("Type: " + o.Type);
        }
    }

    [JsonObject]
    public class JiraIssue
    {
        [JsonProperty("id")]
        public int Id { get; set; }
        [JsonProperty("fields/issuetype/name")]
        public string Type { get; set; }
    }
    /// <summary>
    /// Custom converter that allows mapping a JSON value according to a navigation path.
    /// Credits to: http://stackoverflow.com/users/3887840/amit-kumar-ghosh
    /// </summary>
    class ConventionBasedConverter : JsonConverter
    {
        public override bool CanConvert(Type objectType)
        {
            return typeof(JiraIssue).IsAssignableFrom(objectType);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            var daat = JObject.Load(reader);
            var issue = new JiraIssue();

            foreach (var prop in issue.GetType().GetProperties(BindingFlags.Public | BindingFlags.DeclaredOnly | BindingFlags.Instance))
            {
                var attr = prop.GetCustomAttributes(false).FirstOrDefault();
                if (attr != null)
                {
                    var propName = ((JsonPropertyAttribute)attr).PropertyName;
                    if (!string.IsNullOrWhiteSpace(propName))
                    {
                        //split by the delimiter, and traverse recursevly according to the path
                        var conventions = propName.Split('/');
                        object propValue = null;
                        JToken token = null;
                        for (var i = 0; i < conventions.Length; i++)
                        {
                            if (token == null)
                            {
                                token = daat[conventions[i]];
                            }
                            else {
                                token = token[conventions[i]];
                            }
                            if (token == null)
                            {
                                //silent fail: exit the loop if the specified path was not found
                                break;
                            }
                            else
                            {
                                //store the current value
                                if (token is JValue)
                                {
                                    propValue = ((JValue)token).Value;
                                }
                            }
                        }

                        if (propValue != null)
                        {
                            //workaround for numeric values being automatically created as Int64 (long) objects.
                            if (propValue is long && prop.PropertyType == typeof(Int32))
                            {
                                prop.SetValue(issue, Convert.ToInt32(propValue));
                            }
                            else
                            {
                                prop.SetValue(issue, propValue);
                            }
                        }
                    }
                }
            }
            return issue;
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
        }
    }
}

Thank you for this. I spent 20 minutes looking at answers on SO that danced around this simple solution.

@MinnowTman - thank you! That gist really helped me out.

I've posted a solution with classes support here (based on @MinnowTman code)
https://stackoverflow.com/a/67932675/4601817