Remove duplicates from drop down list

[aggie24193]

I have a spreadsheet with three columns of data. Column 1 and 2 have multiple matches. Column 3 are all unique values.
I am trying to make three drop downs that only show unique values in each based on the selection from the previous drop down. However, only tutorials I can find have 2 columns of data not 3. When I try to expand to three columns, my second column drop down list includes duplicate values. How do I remove them?

Please tutorial I followed: http://www.xelplus.com/find-multiple...rop-down-list/
it's from excel VP Leila Gharani

Another tutorial I used is:
http://www.xelplus.com/excel-depende...-tabular-data/
also by Leila Gharani

 

[Fluff]

Duplicate https://www.mrexcel.com/forum/excel...multiple-matches-post5078283.html#post5078283

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