Hi @taufik_maggangka, I had a look.
The easiest way is to not work with choice filter here, but with skip logic most likely. This will only work if you know the name of the people beforehand. But you basically repeat the list (as I had shown in the file I sent you, including the group around it. And then you make the group relevant to the selection of the school chosen in the prior question. While it will look like a lot of duplication in your Excel file, but in the form itself they will only see the one they selected.