How to revoke permission form a folder?

There are multiple users in ubuntu in my system. Let’s say users are X1, X2, X3, .. , Xn

Now in a Storage HD mounted at /data/ each of them contains one folder. User X1 is sudoers. Each time a new user (X*) comes, X1 creates a new folder by his username (X*) in /data/ and gives permission by

setfacl -m u:X*:rwx X* chown X* X* 

Now to see the folder persmission we use,

# file: X* # owner: X* # group: N1 user::rwx user:X*:rwx group::rwx mask::rwx other::r-x 

Now every user in the usergroup can see the folder content of other users. as they can enter to each other’s designated folder. How to restrict them each entering other’s folder.