Cubase automatically groups notes under beams. You can determine how notes are grouped.

You can display subgroups after four sixteenth notes under a beam by activating Beam Subgroups in the Score Settings dialog (StaffOptions tab).

Figure 1. Beam Subgroups deactivated
Figure 2. Beam Subgroups activated

If you also activate 16th Subgroups, subgroups appear after only two sixteenths.

Figure 3. Beam Subgroups with 16th Subgroups activated

In the Score Settings dialog (ProjectNotation Style page), you can find options for beam appearance in the Beams category. These settings are global for all staves.