My goal is to organize a shared workspace in a cloud storage service with the following structure:

📁 Work
├── 📁 Common ← shared with everyone
├── 📁 Alice ← accessible only to Alice
├── 📁 Bob ← accessible only to Bob
└── 📁 Carol ← accessible only to Carol

I want to share the parent folder Work with all members of the group, so that in their view the shared item appears as a single folder called "Work". However, when they open it, each member should only see the contents they are entitled to access: the Common subfolder (visible and editable by everyone) plus their own personal subfolder. Members should not be able to see or open anyone else's personal subfolder.

In other words, what I am looking for is a way to share a single parent folder while assigning dedicated, differentiated permissions to its subfolders — ideally with hidden or inaccessible branches, rather than just greyed-out entries.
Why This Design

From a user-experience perspective, this is the most natural arrangement:

Everyone works inside one clearly identified space ("Work") instead of receiving several disconnected shared items scattered in their "Shared with me" section.
Each person keeps a private area for their own files without forcing the owner of the account to manage and share four separate folders as independent elements.
New members can be onboarded by granting them access to the parent structure with the appropriate subset of subfolder permissions.

The Current Limitation

In the services I have tested (including Proton Drive), folder sharing permissions are inherited top-down as an indivisible block: whoever receives access to a parent folder automatically gets access to all of its contents, at every level of the tree. There is no option to:

hide a subfolder from certain recipients,
exclude specific users from a branch of the shared tree,
or assign per-subfolder permissions within the same shared item.

An alternative approach — sharing each subfolder separately and using naming conventions like "Work – Common", "Work – Alice", etc. — works functionally, but produces multiple disconnected shared items instead of the single, coherent folder view I am aiming for.

Password-protected public links do not solve it either, since access there is tied to knowing a secret rather than to the recipient's identity, and it cannot be revoked selectively.
What I Am Looking For

A service, feature, or proposed design that supports per-subfolder access control inside a single shared parent folder, specifically:

A single shared element ("Work") visible to all invited members.
Per-subfolder role-based permissions (e.g., Common: read/write for everyone; Alice: read/write for Alice only; others: no access, ideally invisible).
Selective revocation: removing a person's access to one subfolder without affecting the rest of the structure.
End-to-end encryption would be a strong plus, given the privacy-oriented services where this use case arises.