It is important to work on not only the shifting motion but also how to use the shifting in the short exercises, as you can see in Introducing the Positions, vol.1 no.85 through no.88.
I highly recommend to use below exercises to learn changing the position with remaining finger and then play the next note on the 3rd position.
sheet music is available below.
The audio in Youtube:
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Another article: Introducing the Positions Vol. 1 no.87 by Hohmann