Often times I download PDFs online and I would like to create nested outline tabs so that it's not so cluttered. For example, instead of having Chapter 1, Chapter 1.1, Chapter 1.2, Chapter 1.3, etc. have the ability to nest all sub chapters under Chapter 1. This is great for big textbooks or when I want to organize my notes. It's definitely already a feature Goodnotes 5 supports considering several PDF's have nested outline tabs, but for whatever reason, I cannot make my own nested tabs.

This can easily be done by click and dragging tabs to nest them under a parent tab.