.htaccess - 将子文件夹重写为父级，可以访问父级中的其他文件

I am trying to create a RewriteRule which would allow me to hide the subfolder name from the URL. It seems pretty straightforward, although I would also like to retain access to the files in the parent folder, and I can't work out how to achieve this and whether this would be possible at all. To make it a bit more clear, my file tree is as follows:I am trying to create a RewriteRule which would