Use a table to keep users and access_tab something like below.
create this table in both the qvws.
Then select document chain transfer state option. As you have this access table in both the qvws so when users login to first qvw would have the same access_tab values when they login to second qvw via doc chain.
Now to get the value per users, you can use either section access or simple on open trigger that would match the OSUser() function value with the user name or id in the table and then set the field (access_tab) value accordingly.
Then in the second qvw you can manage the visibility of the tab by setting the condition in the sheet properties.