SQL Server 2014

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create table test (
 Id int identity primary key, 
 Column1 varchar(30),
 Column2 varchar(30)
);
insert into test (Column1, Column2) values
('a/b/c', 'apple/banana/cucumber'), 
('d/e/f', 'orange/prune/onion');
2 rows affected

CREATE FUNCTION dbo.fnString_Split
(
    @str    nvarchar(4000), 
    @delim  nchar(1)
)
RETURNS TABLE 
WITH SCHEMABINDING 
AS 
RETURN
(
  WITH RCTE AS (
    SELECT 
      1 AS ordinal
    , ISNULL(NULLIF(CHARINDEX(@delim, @str),0), LEN(@str)) AS pos
    , LEFT(@str, ISNULL(NULLIF(CHARINDEX(@delim, @str),0)-1, LEN(@str))) AS value
    UNION ALL
    SELECT 
      ordinal+1
    , ISNULL(NULLIF(CHARINDEX(@delim, @str, pos+1), 0), LEN(@str))
    , SUBSTRING(@str, pos+1, ISNULL(NULLIF(CHARINDEX(@delim, @str, pos+1),0)-pos-1, LEN(@str)-pos )) 
    FROM RCTE
    WHERE pos < LEN(@str)
  ) 
  SELECT ordinal, value
  FROM RCTE
);
select 
  t.Id
, ca.Column1
, ca.Column2
from test t
cross apply (
  select 
    s1.ordinal
  , s1.value as Column1
  , s2.value as Column2
  from dbo.fnString_Split(t.Column1,'/') as s1
  join dbo.fnString_Split(t.Column2,'/') as s2
    on s1.ordinal = s2.ordinal
) ca;


Id
Column1
Column2


1
a
apple

1
b
banana

1
c
cucumber

2
d
orange

2
e
prune

2
f
onion