sftp restricted access on ubuntu

@jtittle or anyone - Please help

I have user-1 which is already added to sftpusers group and can do sftp successfully

Now I have created new user - user-2 and have added it to sftpusers group

Issue 1) I am not able to do sftp using user-2 Please help what else needs to be done to make sure user-2 can also do sftp

Issue 2) I want user-2 to have only access to the following path and its sub-directories (read, write, execute) /home/user-1/htdocs/public/book

Also I want user-1 to continue to have access (read, write, execute) /home/user-1/htdocs/public/book

Looking forward for help