Column A is a smaller set of values from Column B. Column C is related to Column B.
You can think of this data as Countries in Columns A and B. Column C contains capital cities of countries in Column B.
I need to output correct capital cities for Column A countries by matching with Column B.
This is simiar to this question: If two cells match, return value from third
but I need it applied to Libre Office Calc.
VLOOKUP is the function you're looking for.