테이블 함수를 이용하시면 좀 편하게 쿼리가 가능 합니다...

create table TREE  (
 
  ID   VARCHAR(10)
 ,PARENT_ID VARCHAR(10)
 ,CNT  INT
 ,RGDATE  VARCHAR(10)
)

INSERT INTO TREE VALUES('1','', 1, '2014-01-01')
INSERT INTO TREE VALUES('2','1', 2, '2014-01-08')
INSERT INTO TREE VALUES('3','1', 3, '2014-02-11')
INSERT INTO TREE VALUES('4','1', 1, '2014-04-11')
INSERT INTO TREE VALUES('5','', 3, '2014-02-11')
INSERT INTO TREE VALUES('6','2', 2, '2014-08-01')
INSERT INTO TREE VALUES('7','2', 4, '2014-07-25')
INSERT INTO TREE VALUES('8','', 1, '2014-04-27')
INSERT INTO TREE VALUES('9','5', 5, '2014-01-01')
INSERT INTO TREE VALUES('10','5', 9, '2014-01-01')
*/
WITH RES ( PARENT_ID , ID ,RGDATE, LEV )
AS (
SELECT PARENT_ID ,  ID , RGDATE , 1 LEV   
  FROM TREE
 WHERE PARENT_ID = ''
  UNION ALL
SELECT    A.PARENT_ID ,   A.ID , A.RGDATE,  B.LEV + 1 LEV
  FROM TREE A JOIN RES B ON A.PARENT_ID = B.ID
 )
  SELECT   PARENT_ID, ID ,RGDATE, LEV
   FROM RES
 ORDER BY LEV , ID
 
 --------------------------------------------------------------------
 CREATE function [dbo].[UTF_DEPT] (@PARENT_ID  VARCHAR(10))
 
RETURNS  @RES  TABLE
(
  PARENT_ID VARCHAR(10)
 , ID   VARCHAR(10)
 ,CNT  INT
 ,RGDATE  VARCHAR(10)
 ,LEV INT
)

as
 BEGIN
;WITH RES ( PARENT_ID , ID ,CNT,RGDATE, LEV )
AS (
SELECT PARENT_ID ,  ID ,CNT, RGDATE , 1 LEV   
  FROM TREE
 WHERE PARENT_ID = @PARENT_ID
  UNION ALL
SELECT    A.PARENT_ID ,   A.ID ,A.CNT, A.RGDATE,  B.LEV + 1 LEV
  FROM TREE A JOIN RES B ON A.PARENT_ID = B.ID
 )
 INSERT @RES
  SELECT  PARENT_ID, ID ,CNT,RGDATE, LEV
   FROM RES
  UNION ALL
SELECT @PARENT_ID ,  ID ,CNT, RGDATE , 0 LEV   
  FROM TREE
 WHERE ID = @PARENT_ID
 ORDER BY LEV , ID
           
     RETURN

 END
 ------------------------------------------------------------------
 
 
 
SELECT A.ID , A.CNT , SUM(B.CNT)TOTAL_CNT ,A.RGDATE , MAX(B.RGDATE) LAST_DATE
  FROM TREE A 
  CROSS APPLY
  (
 SELECT CNT , RGDATE
   FROM dbo.UTF_DEPT(A.ID) ) AS B
  
 GROUP BY A.ID ,A.PARENT_ID ,A.CNT ,A.RGDATE
 ORDER BY CAST(ID AS INT)
 

감사합니다.

원하는결과와  많은 도움이 되었습니다~