Quick question...

Is it possible to add a couple command buttons for different selections and it do the same thing as a Data Validation selection dropdown?

I have a selection box that is data validated and when it is selected it actually controls another dropdown from a couple tables. For instance if I select: Proteins from the first dropdown I get a list of food sources of Proteins. If I select Carbs I get a list of Carbs. Now for convenience sake I had a thought if the dropdown was to confusing for people is there a way to do the same thing with command buttons or form buttons?