Create a New Tile on macbook - can not save files

Hi all, I am going trough tutorial Ruby’s Adventure. And I am creating a Tile inside a new folder under Assets → Art → Tiles

My project is under Documents/Projects/Personal/Unity/Ruby And when I try to save new Tile I can not navigate to Ruby/Assets/Art/Tiles. The system only allows me to store under Documents and can not navigate any further… It is frustrating…

Any Idea what am I missing? How to fix this?

If it will help anyone, I saved Folder on ~/ and it is working now.