oracle 嵌套查询引用父查询字段问题

select Mamx.SalesMachineId ,
(SELECT substr(replace(replace(replace(replace(XMLAGG(xmlelement("row",xmlforest(temptab.COLTEST as "ID"))),'',''),'',''),'',''),'',''),2) from
(select ' '||lpad(cast(ShiShiKucun as varchar2(5)),5,'_____') as COLTEST
from aokSalesMachineMx mxz where mxz.SalesMachineId=Mamx.SalesMachineId order by mxz.TongDao asc) temptab) ShiShiKucun
from aokSalesMachineMx Mamx group by Mamx.SalesMachineId;

Mamx.SalesMachineId标识符无效，该如何解决。谢谢！

查询字段不正确，检查一下语句