using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        // Group collection

        List<Group> adGroups = new List<Group>() { 

                new Group() { Name = "WT1", Sid = "Sid1"} ,

                new Group() { Name = "WT3", Sid = "Sid2" }  

            };

        // GuidelinesWorkTeam collection

        List<GuidelinesWorkTeam> gwtItems = new List<GuidelinesWorkTeam>() { 

                new GuidelinesWorkTeam() { Name = "WT1", Sid = "Sid1"} ,

                new GuidelinesWorkTeam() { Name = "WT2", Sid = "Sid2" }  

            };

        // LINQ Query

        var result = gwtItems.Where(gwtItem => adGroups.Any(adGroup => gwtItem.Sid == adGroup.Sid && gwtItem.Name != adGroup.Name));

        foreach(var item in result)

        {

            Console.WriteLine(item.Name);

            Console.WriteLine(item.Sid);

        }

    }

}

​

public class Group

{

    public string Name { get; set; } 

    public string Sid { get; set; }

}

​

public class GuidelinesWorkTeam

{

    public int Id { get; set; }

    public string Name { get; set; }

    public string Sid { get; set; }

    public bool Active { get; set; }

}