sql function recycle and split

CREATE FUNCTION [dbo].[ufn_Admin_GetSubGroupByGroupId](@parentId AS INT) RETURNS TABLE 
AS 
RETURN 
  WITH SubsCTE 
  AS 
  ( 
   -- Anchor member returns a row for the input manager 
   SELECT GroupId 
   FROM dbo.tb_Group 
   WHERE GroupId = @parentId 
 
   UNION ALL 
 
   -- Recursive member returns next level of subordinates 
   SELECT C.GroupId 
   FROM SubsCTE AS P 
     JOIN dbo.tb_Group AS C 
       ON C.Parent = P.GroupId 
  ) 
  SELECT * FROM SubsCTE; 

select * from [dbo].[ufn_Admin_GetSubGroupByGroupId](@parentId)

CREATE   FUNCTION   [dbo].[ufn_SplitStr](@SourceSql VARCHAR(8000), @StrSeprate VARCHAR(100))  
 RETURNS   @temp   TABLE(UniqueId INT IDENTITY(1, 1), Id   VARCHAR(100))  
AS    
    BEGIN  
  DECLARE @ch AS VARCHAR(100)  
  WHILE(@SourceSql <> '')  
   BEGIN  
    IF charindex(@StrSeprate, @SourceSql, 1) > 0
     BEGIN
      SET   @ch=left(@SourceSql, charindex(@StrSeprate, @SourceSql, 1) - 1)
      IF @ch <> ''
       BEGIN  
       INSERT   @temp   VALUES( @ch )  
      END
      SET   @SourceSql = stuff(@SourceSql, 1, charindex(@StrSeprate, @SourceSql,

1), '')  
     END
    ELSE
     BEGIN
      INSERT   @temp   VALUES( @SourceSql ) 
      BREAK
     END
   END
  RETURN  
   END