How would you approach and structure this input in an accessible way?

Hi everyone, hope you're doing well! 🙂 I'm struggling to find a good way to structure this input, which is a dropdown but it also has a searchbar in it. I've thougth of different ways to structure it, taking in accout keyboard navigation and screen readers. It's part of a search form, where there are other two inputs like this and they are consecutives (what I mean is that you cannot open the second and the third if you didn't select an option from the first one, and so on for the other two) I found that datalist is the element that get closer to it, but it's hard to customise. Any idea? Thanks in advance for your time! 🙂