ABAP New Syntax: Deep Table issue

Hi All,

I am facing below issue with LT_ITEM table which is deep structure :

et_output = VALUE # ( FOR LS_ITEM IN LT_ITEM

( DEL_NUM = LS_ITEM-DELNUM

PO_NUM = VALUE #( LS_ITEM-REFDOC[ DOCCAT = 'SO' ]-REFDOC_NUM OPTIONAL )

PO_ITM = VALUE #( LS_ITEM-REFDOC[ DOCCAT = 'SO' ]-REFITM_NUM OPTIONAL ) ).

In above table ET_OUTPUT , only DEL_NUM field comes populated although LT_ITEM-REFDOC has value field for condition DOCCAT = 'SO' .

I tried multiple threads like below but did not get rootcause of the issue. Ccan anyone suggest why PO_NUM and PO_ITM are not populated

https://answers.sap.com/questions/748917/new-syntax-for-deep-structure--an-internal-table-i.html