Try something like below:
SELECTION-SCREEN BEGIN OF BLOCK b1 WITH FRAME.
PARAMETERS: r1 RADIOBUTTON GROUP g1 USER-COMMAND uc1,
r2 RADIOBUTTON GROUP g1,
r3 RADIOBUTTON GROUP g1.
SELECTION-SCREEN BEGIN OF LINE.
SELECTION-SCREEN PUSHBUTTON (20) text-t01 USER-COMMAND exp.
SELECTION-SCREEN PUSHBUTTON (20) text-t02 USER-COMMAND col.
SELECTION-SCREEN END OF LINE.
SELECTION-SCREEN END OF BLOCK b1.
AT SELECTION-SCREEN.
CASE sy-ucomm.
WHEN 'EXP'.
LOOP AT SCREEN.
IF screen-name = 'R2' OR screen-name = 'R3'.
screen-active = '1'.
screen-output = '1'.
screen-invisible = '0'.
MODIFY SCREEN.
ENDIF.
ENDLOOP.
WHEN 'COL'.
LOOP AT SCREEN.
IF screen-name = 'R2' OR screen-name = 'R3'.
screen-active = '0'.
screen-output = '0'.
screen-invisible = '1'.
MODIFY SCREEN.
ENDIF.
ENDLOOP.
ENDCASE.