Bottom up hierarchy in dependent cascading drop down list

I followed one of the online tutorials to create cascading dependent drop down list.
But this approach only allows me top-down data entry. Lets say I have to set geographical location. First I have to choose continent, then country, then county and then city (this is just simplified example). In order to speed up the process I would like to have the option to fill in the table from down to top: once I set the city excel automatically settles the higher hierarchy. The example above does not allow this option- I have to start from the higher classification.
I could not find the solution online or in these forums. Maybe I am usin wrong keywords. Your help is greatly appreciated.
Sergei

Well, that wouldŽnt hurt... But if I would have to choose one I would go for bottom-up because it is fastest way to fill in huge table.

Thanks! I was not familiar with the function. I am not sure I interpret it right but I am afraid I cannot apply it in my case.
I have roughly million entries in rows. For each entry I have multiple features to annotate from drop down list. Many features have subsequent cascading hierarchy.
Of-course the work of annotations will be divided between many team members but I have to create suitable and user friendly spreadsheet for that.

Ok here is a basic example in a file. If I could just set up a function that would able me to fill the table starting from "substrate level 3"

No, this is separate table down there, I should of deleted this one. I am using data between K2 to T9 (and R19). Perhaps this on one of the most complex hierarchy cases in my dataset, others are smaller and simpler. Is there a way to make it bottom-up?