int count=0;
var z = testdict
.GroupBy(x => new { x.Value.Item2, x.Value.Item3 })
.ToDictionary(x => ++count,
x => new Tuple<string, string, int>
(
x.Key.Item2, x.Key.Item3, x.Count()
));
4
solved Create new Dictionary with group and count based on existing Dictionary with tuple