The image in the OP looks like Finale output to me. At least I assume by the fact that it’s complete and edited, including all the Chinese text, that it is not 276180876’s own work in Dorico, but a published example of changing between condensed and open score for choir.
One way to do this in Dorico is to use condensing to combine Soprano+Alto and Tenor+Bass onto shared staves. This currently has some serious limitations that have been discussed in many other threads.
Another way is to add two more instruments for SA and TB in setup mode (in addition to the 4 separate SATB staves), write the music on the staves where you want it to appear, and use system breaks in the score at the switch points.
I fear that this mountain of information with multiple possible approaches will be impossible to convey over a language barrier.