Hi Alok,
you could try to create the F4 in GET_V method by an outbound plug call, for example:
CREATE OBJECT rv_valuehelp_descriptor TYPE cl_bsp_wd_valuehelp_navdescr
EXPORTING
iv_outbound_plug = 'OP_PROJECT'.
In the outbound plug, create a popup window with your F4 help and set an on close event, for example (method OP_PROJECT):
me->ao_popup = comp_controller->window_manager->create_popup( iv_interface_view_name = 'AIC_PROJECT_VH/MainWindow'
iv_usage_name = 'CUProjectValueHelp'
iv_title = lv_title ).
me->ao_popup->set_on_close_event( iv_view = me iv_event_name = 'SELPROJECT' ).
Best Regards,
Christoph