Viewing Structure of a Source File
You can examine the structure of the file currently opened in the editor using the Structure tool window (Alt+7) or the Structure popup (Ctrl+F12).
By default, IntelliJ IDEA shows all classes, methods, and other elements of the current file. To toggle the elements you want to show, click the corresponding buttons on the Structure tool window toolbar. For example:
Click to show class fields.
Click to show inherited members.
Click to show included files.
To show class members in the Project tool window
Right-click the Project tool window title bar and select Show members from the context menu.