There are many examples of a particular compositional technique, so I was wondering if it had a name. The example closest to me right now is Beethoven piano sonatina in F, 2nd movement (Anhang 5), starting around measure 27. We see a chromatic scale that leads perfectly into the intro theme. I love when I see it - a seemingly unrelated musical idea that just so naturally leads back to something we've heard before. Is it just good composition or is there a term for it?
If anyone is curious, here's the section OP mentions:
I can't think of any name for this particular technique, other than "chromatic scale that fills in the four-measure phrase and leads back to the theme," but that doesn't roll off the tongue all that well.
There is a branch of music theory called Sonata Theory, and one of their big points is the role of particular types of punctuations in the sonata form. One of these is called the Medial Caesura, and affiliated with that concept is the notion of the "caesura fill," where some musical element "fills" in what would otherwise be a complete rest in the music. So although the section you mention isn't a Medial Caesura, we do nevertheless see a punctuation and rest in the left hand starting in m. 3 and a "caesura fill" chromatic scale in the right hand. You may find that term helpful, but be careful when using it somewhere that isn't a Medial Caesura!