Hi Suize,
There is no "standard selection screen" ![]()
Just look on the simple help sample: Custom Logic and BADI - SAP Business Planning and Consolidation, version for SAP NetWeaver - SAP Library
Parameters are passed explicitly - like YEAR=1 Etc...
If you are talking about selection of members - then you will receive the selected members in scope. Look on ct_data - it will contain records selected by scope (QUERY=ON).
Vadim