For this directory structure:
.
|-- README.txt
|-- firstlevel.rb
`-- lib
|-- models
| |-- foo
| | `-- fourthlevel.rb
| `-- thirdlevel.rb
`-- secondlevel.rb
3 directories, 5 files
The glob would match:
firstlevel.rb
lib/secondlevel.rb
lib/models/thirdlevel.rb
lib/models/foo/fourthlevel.rb