LINQ: Query GROUP BY conditional COUNT

How is it possible to move this type of operation to Linq ... in SQL:

  

COUNT (CASE WHEN VALUE="EXAMPLE" then 1 else = 0 END)

Within a GROUP BY statement

In linq?

from
join...
from...
group new
{
    contador = tabla.Count(x=> x.VALOR =="EJEMPLO")
} into g
select new
{
    contador = g.Key.contador
}

Update : it seems correct but the details of the exception:

  

The nested query is not supported. Operation1 = 'GroupBy'   Operation2 = 'MultiStreamNest