How to transfer data from BOPF to custom feeder class (FPM based application)

I am modifying EHS ( Enviorment, Health and Safety ) standard application. I already created 2 custom tabs they use BOPF object to get/set data. They are working fine. I need to create 3rd tab, this tab displays data from a custom table ( Z- table ). I created a custom feeder class. My problem is to read data from the z-table I need key information like material number from BOPF object. How could I access the correct instance of BOPF object to get the material number in the custom feeder class.

Any help is greatly appreciated.