Hey,
I am sorry to ask such basic questions here but I am searching for a long time already how to group bars. Especially how to force bars into groups of four and how to force a line break (hope that is the right word in English; I mean how to force a bar to appear at the beginning of the next line instead of the old one; in German it is “Zeilenumbruch”). Thanks for your help.
Oliver
It’s called system breaks and frame breaks in D. In Engrave mode, select the first item you wish to appear on a new line and hit shift+s. Shift+f will move it to the next page (frame)
You have two options:
1.) you can go into engrave mode and click on the bar lines where you want the start of a new line and hit “shift-S” to create a system break and move the measures down to the next line
2.) better still, you can try the new “casting off” features introduced in 1.1. Go to layout options and select that you want Dorico to cast off with 4 measures per system. That should do all the hard work for you! 
The new casting off options are on the ‘Staves and Systems’ page of Layout Options.
What if I want five bars on the first line only, then four from then on. There is a pick up bar in something I am transcribing, but the pick up bar is 4/4, like the rest of it. I did not see the options specified in the manual:
“In the Properties panel, activate Group first bar as pick-up in the Time Signatures group.”
I did not see any “Group first bar as pick-up”. I was hoping if I did that, I might get five on the first line. Is that possible? Thanks!!!
You can override the casting off setting with regular system breaks.
Use this method on the first system:
https://steinberg.help/dorico/v1/en/dorico/topics/engrave_mode/engrave_mode_systems_making_from_selection_t.html
Fantastic!! Works, thank you!!!