You can specify the order in which your learners will take the longread, turn on the chapters numeration, and enable a button that takes readers to a new chapter. 

To start managing navigation settings of a longread, click the Settings link at top right corner and choose the Navigation tab.

Navigation Mode

Specify whether your users will have to take longread chapters one after one or randomly. 

Chapter Numbering

Turn on and turn off chapter numbering by dragging the slider.

That's how chapters list looks like with numbering enabled:

And if numbering is turned off, it looks like this:

Next Chapter Button

Add a button to move to a next chapter at the end of a previous chapter with the help of this slider.

If the option is on, the chapter looks like this: