sql - Multi-level Group By clause is not allowed in a sub query -

the query running fine in query design when use tr.docno field in report. error msg pops :

multi-level group clause not allowed in sub query. 

any ideas how can fix

select t.traid,             iif(t.trawrhidto,"purchase"," sales ") formsorp,             t.tradocnoid,             w.wrhname,             ts.trsprice,             ts.trsvatrate,            ts.trsauxfield,             wi.whiadjustment,             w.wrhcountry,            t.tradate tdate,             ts.trssubtotalgross,            c.cstname cname,             tr.docno          (select tbltransactionssc.tradocnoid docno             tbltransactionssc            (((tbltransactionssc.traid)=[forms]![frmreturns]![tratraid]))) tr       tblwarehouse w            inner join ((tbltransactionssc t left join tblcustomer c on t.tracstid = c.cstid)              inner join (tbltransactionssubsc ts             left join tblwarehouseitem wi on ts.trswhiid = wi.whiid) on t.traid = ts.trstraid) on w.wrhid = t.trawrhid       (((t.traid)=[forms]![frmreturns]![traid])); 

you missing comma check it

select t.traid,             iif(t.trawrhidto,"purchase"," sales ") formsorp,             t.tradocnoid,             w.wrhname,             ts.trsprice,             ts.trsvatrate,            ts.trsauxfield,             wi.whiadjustment,             w.wrhcountry,            t.tradate tdate,             ts.trssubtotalgross,            c.cstname cname,             tr.docno,          (select tbltransactionssc.tradocnoid docno             tbltransactionssc            (((tbltransactionssc.traid)=[forms]![frmreturns]![tratraid]))) tr       tblwarehouse w            inner join ((tbltransactionssc t left join tblcustomer c on t.tracstid = c.cstid)              inner join (tbltransactionssubsc ts             left join tblwarehouseitem wi on ts.trswhiid = wi.whiid) on t.traid = ts.trstraid) on w.wrhid = t.trawrhid       (((t.traid)=[forms]![frmreturns]![traid]));