DECLARE 
  @t TABLE ( [id] INT, [elementid] INT )
;
INSERT
INTO 
  @t( [id], [elementid] )
VALUES
  ( 1, 1 ),
  ( 1, 2 ),
  ( 1, 3 ),
  ( 2, 1 ),
  ( 2, 2 ),
  ( 2, 3 ),
  ( 3, 1 ),
  ( 3, 2 ),
  ( 4, 5 ),
  ( 5, 5 )
;
WITH
t1 AS (
  SELECT
    [id],
    [min] = MIN( [elementid] ),
    [max] = MAX( [elementid] ),
    [cnt] = COUNT( [elementid] )
  FROM
    @t 
  GROUP BY
    [id]
),
t2 AS (
  SELECT
    *,
    [rn]  = DENSE_RANK()
            OVER (
              PARTITION BY 
                [min],
                [max],
                [cnt]
              ORDER BY
                [id] )
  FROM
    t1
),
t3 AS (
  SELECT
    [min],
    [max],
    [cnt],
    [gr] = ROW_NUMBER() OVER ( ORDER BY 1/0 )
  FROM
    t2
  GROUP BY
    [min],
    [max],
    [cnt]
  HAVING
    MAX( [rn] ) > 1
)
SELECT
  t3.[gr],
  t1.[id]
FROM
  t3
  INNER JOIN t1 ON (
        t1.[min] = t3.[min]
    AND t1.[max] = t3.[max]
    AND t1.[cnt] = t3.[cnt] )
;