Hello
Firstly calculate current month using sy-datum(date) .
lv_month = date+4(6).
loop at my_control-cols into wa.
if wa-index <> lv_MONTH. "your hidden column (Column which is not equal to current month)
wa-invisible = 1. OR wa-input = 0.
endif.
modify my_control-cols from wa.
endloop.