declare @table1 TABLE (sess_id int, bl_sess_id int)  
	
INSERT INTO @table1
	([sess_id], [bl_sess_id])
VALUES
(78,394),(81,301),(100,379),(159,271),(195,288),
(202,334),(204,301),(215,389),(217,357),(269,301),
(271,502),(280,334),(301,271),(318,195),(323,301),(326,357),(334,204),(343,02),
(346,195),(349,542),(350,0),(357,301),
(365,404),(366,100),(372,404),(373,301),(374,301),(375,0),(379,334),(381,202),
(389,269),(394,357),(399,349),(403,349),
(404,560),(411,487),(426,373),(428,373),(432,487),(442,0),(453,301),
(457,204),(466,349),(470,366),(474,426),(481,301),(487,564),(491,349),(497,301),
(502,271),(271,271),(502,601),(601,271),(1,2),(2,1),(1,15),(15,2),(2,3);

declare @roots TABLE (sess_id int) 
insert @roots values (78), (81), (1);

WITH N_TABLE AS

(SELECT X.sess_id, X.bl_sess_id,
        MAX(CASE X.gr WHEN 0 THEN X.rn END) AS sess_rn,
        MAX(CASE X.gr WHEN 1 THEN X.rn END) AS bl_sess_rn
 FROM (SELECT T.sess_id, T.bl_sess_id, S.gr, S.temp_id,
                DENSE_RANK() over(ORDER BY S.temp_id) AS rn
       FROM @table1 T
       CROSS APPLY(values (0, T.sess_id), (1, T.bl_sess_id)) S(gr, temp_id)
 ) X
 GROUP BY X.sess_id, X.bl_sess_id
)

,T AS 
(
	SELECT 
	        0 AS Chain_depth,
		S0.sess_id AS Start, 
		S0.sess_id AS Parent, 
		S0.bl_sess_id AS Child, 
		CHAIN = CAST(CONCAT('-', S0.sess_id, '-', S0.bl_sess_id, '-') AS VARCHAR(1024)),
                b.result as BIN_CHAIN
		
		
	FROM N_TABLE S0
		INNER JOIN @roots r ON r.sess_id = S0.sess_id
		
                CROSS APPLY dbo.fnSetBit(convert(BINARY(256), 0), S0.sess_rn) a
                CROSS APPLY dbo.fnSetBit(a.result, S0.bl_sess_rn) b		
		
		
	UNION ALL 
	
	SELECT 
	        a.Chain_depth + 1 AS Chain_depth,
	        a.start, 
	        a.Parent, 
	        a.Child, 
	        a.chain, 
	        i.result AS BIN_CHAIN
	        
	        
	FROM (SELECT 
	             S1.Chain_depth,
	             S1.Start, 
	             S2.sess_id AS Parent, 
		     S2.bl_sess_id AS Child, 
		     S2.bl_sess_rn AS Child_rn,
		     CHAIN = CAST(CONCAT(S1.CHAIN, S2.bl_sess_id, '-') AS VARCHAR(1024)),
		     s1.BIN_CHAIN
	      FROM T S1
		INNER JOIN N_TABLE S2 ON S1.Child = S2.sess_id
		
                CROSS APPLY dbo.fnMatchBit(s1.BIN_CHAIN, S2.bl_sess_rn) as BIN_MATCH

	      WHERE BIN_MATCH.result = 0
	      ) as a
	      
	CROSS APPLY dbo.fnSetBit(a.BIN_CHAIN, a.Child_rn) as i

)


SELECT 	Start, 
		Parent, 
		Child, 
		CHAIN,
		BIN_CHAIN
FROM @roots r
	CROSS APPLY (
		SELECT TOP 1 
				Start, 
				Parent, 
				Child, 
				CHAIN,
				BIN_CHAIN
		FROM T t
		WHERE t.Start = r.sess_id
		ORDER BY Chain_depth DESC
	) t