How can I give another user read/write access to a specific sub folder and the ability to ls the tree but only for the folder they have access to?

I have a user user1 that has a bunch of folders in their home directory, including /home/user1/data/special/files. I have another user user2. I want: - user2 to be able to read/write files/folders in /home/user1/data/special/files - user2 to be able to ls: - / and see /home - /home and see /home/user1 - /home/user1 and see /home/user1/data but not other files/folders in /home/user1 - /home/user1/data and see /home/user1/data/special but not other files/folders in /home/user1/data - /home/user1/data/special and see /home/user1/data/special/files but not other files/folders in /home/user1/data/special I used setfacl to set permissions to /home/user1/data/special/files but it does not let them browse the path.

sudo setfacl -Rm d:u:user1:rwx,u:user1:rwx /home/user1/data/special/files

` I do not want to hange the user/group owner of any of these folders because they ultimately should belong to user1. If it helps, here are more specific details. I'm using a web app/service running on this box. The web app/service is running as user2. In the web app/service, I have to browse/navigate to a folder with the files I want to see. So I have to go to: 1. / then 2. /home then 3. /home/user1 then 4. /home/user1/data then 5. /home/user1/data/special then 5. /home/user1/data/special/files I cannot just enter /home/user1/data/special/files. Is this possible?