Share existing folders

Hello, I currently have a server configured with Zentyal, but I would go to nethserver, when I installed everything on a virtual machine, I would need to understand how to create shares on existing folders.
The server has two HDDs, one for the operating system and the other for data, I realized how not to format the second HDD, but if I want to create shares does not make me choose which folders to share. It 'a solvable problem?

thanks

P.S. This is a translation on-line

Currently, shared folders are sub-directories of /var/lib/nethserver/ibay only.

There is some interest around implementing the customizable path for each item. I think it should be possible, as long as the filesystem where a shared folder is placed supports Posix ACLs.

currently the entire HDD is mounted on the filesystem “/ archive” so I think there are no problems for the ACL.

So I should perform a data backup and then put them back in the shared folders?
P.S. This is a translation on-line