Hi @pamubay, thank you for your reply.
I did not know about page bundle.
After tried to change to your suggest, the page is generated fine.
However exapmle.com/admission/ shows both of admission/index.md and admission/success/index.md.
I think this is the expected result of branch bundle but it is not what I want to do.
I just show the both pages as single page.
any markdown inside Leaf Bundle (except index.md) are not generated automatically.
Inside leaf bundle, the other markdowns are treated as Page Resources.
After that, both example.com/admission/form/ and example.com/admission/success/ are shown fine.
I just solve one more thing. example.com/admisson/ shows a list of both pages but I do not want to show it.
Is there anyway to delete or edit this page?
Well, You need to modify your template list/section code. To ignore both pages.
It’s better to ask the theme maintainer directly, as they know better.