Hide Parameter / Select Option in Selection Screen

REPORT  ZRRSAMPLE.

DATA: d_ucomm LIKE sy-ucomm.

PARAMETERS: p_grpa1(10) MODIF ID a,
            p_grpa2(5) MODIF ID a,
            p_grpb1(2) MODIF ID b.

PARAMETERS: p_acta RADIOBUTTON GROUP rad1 USER-COMMAND act DEFAULT 'X',
            p_actb RADIOBUTTON GROUP rad1.

AT SELECTION-SCREEN.
  d_ucomm = sy-ucomm.

AT SELECTION-SCREEN OUTPUT.
  LOOP AT SCREEN.
    IF p_acta = 'X'.
      IF screen-group1 = 'B'.
        screen-active = 0.
      ENDIF.
    ELSEIF p_actb = 'X'.
      IF screen-group1 = 'A'.
        screen-active = 0.
      ENDIF.
    ENDIF.
    MODIFY SCREEN.
  ENDLOOP.

START-OF-SELECTION.