2.1.1 A page two levels deep

This is 2.2.1: chapter 2 → sub-folder 1-a-subsection (the 1- prefix makes it 2.2) → this page (order: 1 makes it 2.2.1).

The sub-folder got its number from its folder name prefix (1-), while this page got its number from its order: field — the two mechanisms the guide describes, working together.