Actually, I am not using CHGD1-4 event for the enhancement of 'Change History' button.
What I did is to add Object ID in FCODE event before CALL FUNCTION 'BUS_CHANGE_DOCUMENT'.
I added my object like this:
lt_objectid-objectclas = 'ZXXX'.
lt_objectid-objectid = gt_but0bk-partner.
APPEND lt_objectid.
Then
CALL FUNCTION 'BUS_CHANGE_DOCUMENT'
EXPORTING
i_objap = 'BUPA'
i_popup = '2'
TABLES
t_objectid = lt_objectid
It will also work for the button of 'Change History' in Bank Detail.