Is it possible to connect between C13-16 and D/E upper (non-schengen) level directly, without having to walk to the B/C skyline station, and take the train back to T2 again?

How about the other way round, when I have to get from D/E Non-Schengen to C13-16 departures? I remember having made the way from a C16 arrival to the SEN Lounge on level below via a set of staircases close to the "Riegel"