Here you go, though only partially what you are asking: (I think you are referring to automation though, Cubase does not have that Pro Tools function. You have to draw in the automation with the line tool…)
Manual P. 293
Audio events have a fade in and a fade out handle, as well as a volume handle.
These handles provide a quick way to change the fade length or the volume of
events in the Project window.
Event handles become visible if you point the mouse at an event or if you select
To show event handles and fade curves always and not only when you point at
events, in the Preferences dialog select Event Display > Audio, and activate
Show Event Volume Curves Alway