Check out this link to learn how to create dynamic named ranges:

http://www.contextures.com/xlNames01.html#Dynamic

I think the best thing to do is delete the named ranges you don't want one at a time through the Insert|Name|Define dialog. It's the safest bet that you will actually get rid of them

So I am happy you understand.

In terms of named ranges, anything non-numeric of text characters is considered illegal (i.e spaces, dashes, symbols, apostrophes, quotes, etc).

So we need to create ranges that are free of these chars... and because you need to refer to these ranges indirectly, it is best to name them something that you can build from selections you make in the 3 previous dropdown boxes.

So my formula builds a single string from the combination of selections made in your 3 choices. It then removes all the illegal characters through use of nested Substitute() functions. The resulting string should match a named range exactly and so you can now use INDIRECT to refer to the range and extract the corresponding list for use in your 4th dropdown menu.

You seem to get the just of it. So I hope you can manage. If not, post what you are having trouble with and I will endeavour to help.

Good Luck.