Hi,
Try this WDDOMODIFYVIEW, it will help to set focus in Inputfield
DATA lo_element TYPE REF TO IF_WD_VIEW_ELEMENT.
if first_time eq abap_true
CALL METHOD view->get_element
EXPORTING
id = 'Inputfield'"Your required input field
receiving
element = lo_element.
IF lo_element IS NOT INITIAL.
CALL METHOD view->request_focus_on_view_elem
EXPORTING
view_element = lo_element.
ENDIF.
endif.