Ubuntu: Pointing an SFTP user to its working directory without listing other user's directory

I am working on configuring an SFTP server on Ubuntu Server 18.04. I want to create SFTP accounts that point directly to their working directory without listing others. For example if the real working directory on the server is /sftpdir1/sftpdir2/user1, the user should see it as / and not /user1 like when using chrootdirectory: when I login via FileZilla I should find as shown in the image below where I can upload and download files. Update: why not setting chrootdirectory in /etc/ssh/sshd_config If I have more then on user assigned to the same group, so having the same chrootdirectory, any user among will see others' working directory. Or by logging in I don't want the user to see others' dir nor the tree of his/her own working directory: just find / like shown in the image.