How to Make a Smaller Container from End of Larger One

Create a new 1m long container, drag it at the desired place in the timeline (at measure 36 in this case) and make a snapshot (Container >> Make snapshot)

Of course, you can do it also the "traditional way": Select the first 3 measures of that phrase with the span tool and cut it away (right click >> Cut). Then shorten the container by dragging its end. But that's the Stone Age method in my opinion.

You could place the edit cursor in the timeline to where you want the split and CTRL+J to Divide then drag the result into the snippet grid.