Hello Lucio,
Manual assignment will be required at least for the first user to the environment. Once at least one user with the admin rights is there, this admin can assign the correct access to all the other users as mentioned by Alexander. So don't worry about manual assignment for the first time. 
Just add the role for your environment shell (ZBPC_UAU000001) and the other ZBPC_UA* roles corresponding to the task profile, data access profile & user team for the admin and then you can assign access to all the other users from BPC front end.
Hope it works!
Please let me know in case you need any further information!
Regards,
Hari