Create Function hana that call another function

Hi,

I have this error "field or table alias is not allowed as an input of table functions" when try to create function on Hana Studio.

The executed code is like this:

CREATE FUNCTION "FUNCTION_2" (IN strYYYYMMDD_Da NVARCHAR(8), IN strYYYYMMDD_A NVARCHAR(8))

RETURNS TABLE ("DATE_SAP" VARCHAR(8)

             , "HOUR" VARCHAR(2)

             , "MINUTE" VARCHAR(2)

             , "DocEntry SMALLINT")

LANGUAGE SQLSCRIPT AS

BEGIN

RETURN SELECT "T1"."DATE_SAP"

             , "T1"."HOUR"

             , "T1"."MINUTE"

             , "T0"."DocEntry"

        FROM "@MY_UDO_DOC" "T0"

             INNER JOIN "FUNCTION_1" (strYYYYMMDD_Da, strYYYYMMDD_A) AS "T1"

             ON "T1"."DATE_SAP" = "T0"."U_myDateUdo"

        WHERE ifnull("T0"."Canceled",'N') = 'N';

END

Can I create a function  that call another Function?

Regards, Alessandro