I've found it's in Edit Mode -> Select Dropdown -> Select Linked -> Shortest Path. It doesn't even have a shortcut hint!
Hello Benjamin.
You can search for it in your Edit > Preferences > Keymap:
You can also change it there.
Understood. Thank you for the screenshot.
Blender's user interface always make me mad. There are too many weird designs.
Also commonly used buttons are scattering all over the place. May write a addon in future to put them together.