I like to use Eclipse's shortcut Ctrl + O which outlines the current source. Is there an equivalent shortcut in IntelliJ IDEA?
It opens a dialog which allows for quick search of methods and fields in a class.
I haven't used Eclipse for years, so I'm not that familiar with the behaviour you're after - but I believe Ctrl + F12 may do what you want: it is the shortcut for the File structure Popup in the default mapping.
For macOS fn + cmd + F12