Linq kreiranje "pivot -a"

Code:
var output = from a in queryX
                 group a by a.Vrsta_rada into gr
                 select new { Vrsta_rada = gr.Key, Radnici = from r in gr                                                                  
                                         where  radnici.Contains(r.Radnik) 
                                         select r
                 };

Code:
queryX  ..ostaje

 var radnici = queryX.Select(k => k.Radnik).Where(n => n != null).Distinct(); 
 
 
              
 var output = from a in queryX
                 group a by a.Vrsta_rada into gr
                 select new { Vrsta_rada = gr.Key, Radnici = from r in radnici
                                                              join a in gr on r equals a.Radnik into rjouter
                                                             select rjouter.Sum(b => (int?) b.Broj) ?? 0
                                                             
                                                            
                 };

Code:
var radnici = queryX.Select(k => k.Radnik).Where(n => n != null).Distinct();

Code:
public class Radnici

    {

        public string ime { get; set; }
    
    
    }