Build excel file with complex conditional dropdown lists

need to make a condition drop-down list so when I select in level 1 X in level two I get only the items in X's items and when I select Y in level 2, level 3 should offer only the items that belong to level 2 Y in lev 3.
more columns will be added after the dropdown lists columns so the excel file should be able to accept more columns without affecting the dropdown lists