Select the notes that you want to edit, e.g. beam.
Draw a square around the notes OR select the desired notes by clicking on their heads while keeping "ctrl" pressed.
A window "Properties" opens.
Select "Beam Notes".
Or, in fact, any of the other options available to you now: you can tie or slur notes, you can change the direction of the stems, you can enter the enharmonic equivalent, add glissando and many more.