This feature is only supported when the Ruby plugin is installed.
Project Tool Window | View as | Rails
The special Rails view shows logical project structure displaying Controllers, Models, Views, DB migrations, etc as Rails elements rather than files and directories. From the Rails view, you can gain quick access to the application elements and their contents (controller methods, associated and partial views, etc.)
When using the Rails view, note the following:
The Rails view doesn't display the excluded directories, .idea, and script directories.
Controller views that don't have associated Rails actions, are shown under the corresponding controller class node.
All non-view files from controller's views folder are shown under the corresponding controller class node.
All layouts are shown under top-level Layouts node .
Helpers (unclassified) node contains all files, except for the helpers that correspond to controllers by naming conventions.
Views (unclassified) node contains all files and folders except for the controller's views folders.
db (unclassified) node contains all files and folders except for the migrate folder. Instead, migrations are shown in the Models | Migrations node.