Hi Kaustav,
As per your snapshot,
1) Create two radio button groups
Group-1 containing radio buttons
RGP
NGRP
Group-2 containing radio buttons
PO ( Where in you need to bind the visibility of this radio button to boolean attribute)
NON-PO ( Where in you need to bind the visibility of this radio button to boolean attribute)
2) Now on selecting RGP radio button,set the boolean attribute visibility to ABAP_TRUE. Then two radio buttons as per your requirement will be visible.
ie. IF RG_RDP = 'X'. " Radio button RGP is selected.
LO_EL_<NODENAME>->SET_ATTRIBUTE( NAME = ' BOOLEAN ATTRIBUTE NAME'
VALUE = ABAP_TRUE ).
ENDIF.
Hope this helps you.
Thanks
KH