lúc bấy giờ 
at that time [ lúc ] : moment, instant, time; when, at the moment that
[ bấy ] : (1) tender, immature, green, (2) that, that extent
[ giờ ] : time (of the clock), hour, o’clock; now is the time (for sth)
Most Common Compounds Set 1:
Most Common Compounds Set 2 :