How to control access to a directory?

Question

CentOS

Hello, help with a question. There is a server on CentOS 7, there are a bunch of users on it, each with their own projects.
Some users have subprojects that other users are working on, the structure is something like this:
/home/user1/{project1,project2} for project 1/2 owner user1:user1
/home/user2{project1,project2}
What I want to do, but not it turns out: there is, for example, poduser1, which should work quietly (rwx) with project2 for user1, but the rest of the projects of this user should be inaccessible. Throwing users into one group is not good, everyone gets too many rights, I tried it through ACL - it's clumsy at all

Answer 1

remove all projects from users' home folders, and then acl+groups. the main thing is to think over the structure logically and it will not be clumsy :)