In earlier versions of Laravel, you were able to use dot notation to refer to language lines in sub-directories of your translations directory.
So in other words, given the following file structure:
resources lang en site.php admin settings site.php
...you could refer to a line named
resources/lang/en/admin/settings/site.php like this:
This no longer works in Laravel 5. It's entirely possible, however - it's just not obvious, nor particularly well documented.
All you need to do is use forward-slashes, for example: