Questions about users and groups

For more information about users and groups, see Linux Enterprise Application-Linux server application. I recently learned how to configure the SMB service.
The general situation is as follows:
1. Each user has his/her own folder (private space by default)
2. Each department has an internal shared directory under which users in the Department can modify the files or directories they have created.
Other users in the Department only have the permission to view and execute. You can view other departments.
3. All users have a shared directory, and all users can create files and directories. Or who created the file can have full permissions, and other users have the permission to view and execute the file.

It is easy to use smbpasswd-a user in smb to create a user.
Now, how can I configure the second one?
Groupadd groupanme has created a group. Also, mkidir has a folder named by group name.
Now I want to ask how to assign permissions to this group.


You are welcome to write your own configuration ideas and the configuration process. Thank you.