Filter or an excel table can accomplish this task within milliseconds but several people have asked how to do this using drop down lists.
So in this post I am going to use dependent combo-boxes instead of drop down lists.We are not going to use any vba code but we need to create a "calculation" sheet.
Why use combo box? If you decide to change a value in a combo box, other dependent combo box values change instantly. This is not the case with drop down lists.
We are going to create two combo boxes. The first combo box contains unique distinct values from column A. The second combo box contains unique distinct values from column B, based on selected value in the first combo box. See pictures below.