Hola te paso un ejemplo para que te guies mejor
*----------------------------------------------------------------------*
* INCLUDE ZPPFR_BLOQUEO_SEL *
*----------------------------------------------------------------------*
*----------------------------------------------------------------------*
* Pantallas de Selección
*----------------------------------------------------------------------*
SELECTION-SCREEN BEGIN OF BLOCK b01 WITH FRAME TITLE text-b01.
PARAMETERS: p_direc RADIOBUTTON GROUP rb02
DEFAULT 'X' USER-COMMAND UC1,
p_visua RADIOBUTTON GROUP rb02.
SELECTION-SCREEN END OF BLOCK b01.
SELECTION-SCREEN BEGIN OF BLOCK b02 WITH FRAME TITLE text-b02.
SELECTION-SCREEN BEGIN OF BLOCK b03 WITH FRAME TITLE text-b03.
SELECT-OPTIONS: s_usnam FOR ztpp_fr_blq-usnam NO INTERVALS,
s_datum FOR sy-datum.
SELECTION-SCREEN END OF BLOCK b03.
SELECTION-SCREEN BEGIN OF BLOCK b04 WITH FRAME TITLE text-b04.
PARAMETERS: p_bloq RADIOBUTTON GROUP rb01 DEFAULT 'X' MODIF ID rpt,
p_libe RADIOBUTTON GROUP rb01 MODIF ID rpt.
SELECTION-SCREEN END OF BLOCK b04.
SELECTION-SCREEN END OF BLOCK b02.
*----------------------------------------------------------------------*
* Evento AT SELECTION-SCREEN
*----------------------------------------------------------------------*
AT SELECTION-SCREEN OUTPUT.
IF p_direc = 'X'.
LOOP AT SCREEN.
IF screen-group1 = 'RPT'.
screen-active = '0'.
MODIFY screen.
ENDIF.
ENDLOOP.
ELSEIF p_visua = 'X'.
LOOP AT SCREEN.
IF screen-group1 = 'RPT'.
screen-active = '1'.
MODIFY screen.
ENDIF.
ENDLOOP.
ENDIF.
Espero te sirva
