FAILED: ParseException line 1991:0 Failed to recognize predicate 'GROUP'. Failed rule: 'identifier' in subquery source

[#1]

seeing this error while doing inserts

SELECT user_no 
       ,user_name
       ,ref_date
       , 'xxx' BRAND
           ,nvl(SUM
            (
                CASE
                    WHEN product_name        = 'xx'
                    AND  indicator_name     = 'xx'
                    THEN indicator_value
                    ELSE NULL
                END
            ),0) AS SB_TO
           ,
           nvl(SUM
            (
                CASE
                    WHEN product_name        = 'xx'
                    AND  indicator_name     = 'xx'
                    THEN indicator_value
                    ELSE NULL
                END
            ),0) AS SB_GW
           ,
           nvl(SUM
            (
                CASE
                    WHEN product_name        = 'xx'
                    AND  indicator_name     = 'xx'
                    THEN indicator_value
                    ELSE NULL
                END
            ),0) AS xx       
FROM (SELECT pun.user_no , pun.user_name, c.calendar_date AS ref_date , p.xx, p.xx, p.xx, p.channel,  i.xx, sum(f.xx) AS indicator_value
        FROM tabl1 f
        join tab2 c
          on f.time_key         =  c.time_key
        join tab3 p
          on f.product_key        = p.product_key
        join tab4  i
          on f.indicator_key      = i.indicator_key
        join tab5 pun
          on f.xx       = pun.xx
         GROUP by pun.user_no , pun.user_name, c.calendar_date,  p.xx, p.xx, p.xx, p.xx,  i.xx)  
GROUP BY user_no, user_name, ref_date

[#2]

Maybe it's not the only issue, but you have to specify an alias for the subquery. Try doing this and let us know if you have other issues or the same error still remains...