using System;

using System.Linq;

using Newtonsoft.Json.Linq;

​

public class Program

{

    public static void Main()

    {

        JArray array = new();

        array.Add(new JObject(){{ "IntegerValue", 2 }, { "FieldKey", "a" }});

        array.Add(new JObject(){{ "IntegerValue", 1 }, { "FieldKey", "a" }});

        array.Add(new JObject(){{ "IntegerValue", 1 }, { "FieldKey", "a" }});

        array.Add(new JObject(){{ "IntegerValue", 2 }, { "FieldKey", "b" }});

        array.Add(new JObject(){{ "IntegerValue", 2 }, { "FieldKey", "b" }});

        array.Add(new JObject(){{ "IntegerValue", 1 }, { "FieldKey", "b" }});

        var array2 = array.GroupBy(x => new {

                FieldKey = x["FieldKey"],

                StringValue = x["StringValue"],

                BigStringValue = x["BigStringValue"],

                IntegerValue = x["IntegerValue"],

                DecimalValue = x["DecimalValue"],

                DateTimeValue = x["DateTimeValue"],

                BoolValue = x["BoolValue"]

            }).Select(x => x.Key);

        Console.WriteLine(array);

        Console.WriteLine("---------------------------------");

        foreach(var xd in array2)

        {

            Console.WriteLine(xd);

        }

    }

}