How to have comboboxes in this situation?

[thedalek]

Hi folks,

I've got this table structure:

[Attached image]

I'd like to have two different comboboxes with the information of both columns filtered. For example, if I select "Cars" in the first combobox, I should only see "Audi", "BMW" and "Mercedez-Benz" in the other Combobox.

I'm new to the Forum so please let me know if there's something wrong with my question.

Trying to find a solution here but so far no idea!

Thanks in advance!