Pbaldy has a great website that goes over something that you could use. It's in the thread below where he answered a similar question for me.
https://www.accessforums.net/access/...tbox-4593.html
The basic idea is usually summarized using the Country, State, City example. Set your data up accordingly.
Code:
United States Colorado Denver
United States Colorado Colorado Springs
United States Florida Jacksonville
Once the table is ready, you can create a form with cascading combo boxes that use the afterupdate event of the combo box to cascade with each selection. Using the Country, State, City example, you would have a combo box whose recordsource is the Country field of your table. When a country is selected, the State combo box cascades on the value of the Country and so on.
You can get a little more advanced by setting a default value and making the items refresh when a change occurs, but that is the basic idea. Let me know if that helps.