field or table alias is not allowed as an input of table functions

Hi,

I am using SPS 8 version of HANA. I am trying to write a query something like the following in a procedure but it gives me error SAP DBTech JDBC: [7] (at 1669): feature not supported: field or table alias is not allowed as an input of table functions:

The query is

SELECT a."abc",a."nn",....., (SELECT ITEMS FROM <schema_name>."FN_GetItems"(ex."ID",'pqr','')) AS P,ex."gg",...

FROM <schema_name>."Table1" ex where ..........;

Inside my function i am just trying to return a string after doing some select queries and operations. I cannot use scalar UDF because it does not support SELECT queries and if i make it table UDF then i get the above specified error. Can anyone suggest what am i missing or an alternative to achieve my purpose?

TIA.

Nikhil