Dorico currently only lets you ‘centre’ the beam between notes if the interval is a fourth or greater.
I’ve come up with a ‘workaround’ if you want this style for smaller intervals.
It’s easy enough just to grab one end of the beam and drag it down in Engrave mode.
But of course, the stem now connects to the wrong side of the second note.
We can change that with a Custom Notehead. Create a new Notehead Set; duplicate the default Notehead, (then delete the original).
Edit the notehead by switching the positions of the Stem Up SE and Stem Down NW anchor points. (Stem Up SE is normally on the right hand side.)
Now apply the the notehead set to the notehead.
Once set-up, you just have to drag the beam and apply the notehead. Bingo.
This method might also have other uses where a stem on the wrong side is required.