Limited link access to files

I have finally solved the ability to link to a file in the file structure, by using:

  location /wp-content/uploads/filebase {
        autoindex on;
		autoindex_exact_size off;
		disable_symlinks on
    }

This allows free external access to this directory. Thanks to those who helped!

My next problem: the customer wants to be able to send out links to specific directories within the "filebase" directory, and not allow traversal upwards.

Is this possible?