Question: What's the best way to implement directory permission control in git?

[ZheNing Hu <adlternative@gmail.com>]

if there is a monorepo such as
git@github.com:derrickstolee/sparse-checkout-example.git

There are many files and directories:

client/
    android/
    electron/
    iOS/
service/
    common/
    identity/
    list/
    photos/
web/
    browser/
    editor/
    friends/
boostrap.sh
LICENSE.md
README.md

Now we can use partial-clone + sparse-checkout to reduce
the network overhead, and reduce disk storage space size, that's good.

But I also need a ACL to control what directory or file people can fetch/push.
e.g. I don't want a client fetch the code in "service" or "web".

Now if the user client use "git log -p" or "git sparse-checkout add service"...
or other git command, git which will  download them by
"git fetch --filter=blob:none --stdin <oid>" automatically.

This means that the git client and server interact with git objects
(and don't care about path) we cannot simply ban someone download
a "path" on the server side.

What should I do? You may recommend me to use submodule,
but due to its complexity, I don't really want to use it :-(

ZheNing Hu