If you have not mentioned reftable or reffield for a field during building of field catalog , this may happen.

OR

If you use primitive data types (like C,I,N etc) ;, then also you may face problem of filtering not working.

The solution(s) to this problem are
  
1. Specify reftable and reffield for a field.
Ex: Reftable can be MARA ref field can be MATNR for MATNR field
wa_fieldcat-ref_tabname =mara
wa_fieldcat-ref_fieldname =matnr

2. Specify OUTPUTLEN to the limit of primitive data types
 
Ex:
wa_fieldcat-outputlen = '40'.



Serkan AKKAVAK
ABAP Developer & SAP MM SD Consultant
serkurumsal@yandex.com