In one unit of time, that country cannot produce more of any product than the competing country.
Let Country 1 (C1) produce either 1 of product X or 1 of product Y in 1 day.
Let Country 2 (C2) produce either 2 or product X or 2 of product Y in 1 day.
C1 has the absolute disadvantage in both products because it cannot produce more than C2 in either product at the end of the day.