–>This Format will work (Or) Not.

SELECT array_to_json(array_agg(outer))  FROM  (   SELECT       eCPRefAuth_Action_Code_Lookup_Category2 ( SELECT array_to_json(array_agg(Result))  FROM  (   SELECT       eCPRefAuth_Action_Code_Lookup_Category       ,json_agg(          row_to_json(                          (                              SELECT t FROM                              (                                  SELECT eCPRefAuth_Action_Code_Lookup_Code, eCPRefAuth_Action_Code_Lookup_Desc                                  ORDER BY eCPRefAuth_Action_Code_Lookup_Seq_level2                                                            )  AS t(eCPRefAuth_Action_Code_Lookup_Code, eCPRefAuth_Action_Code_Lookup_Desc)                          )                                        )              ) AS available_codes  FROM   tbl_eCPRefAuth_Action_Code_Lookup   GROUP  BY eCPRefAuth_Action_Code_Lookup_Category, eCPRefAuth_Action_Code_Lookup_Seq_level1  ORDER BY eCPRefAuth_Action_Code_Lookup_Seq_level1 ) AS Result ) FROM   tbl_eCPRefAuth_Action_Code_Lookup  )as outer