I have been through the entire Busuu Portuguese course from A1 to B2 three times so decided all I need is to review lessons rather than completing the course a fourth time. But I noticed that, 1 the shading and the position that tells you the last lesson completed isn't there to indicate where you are and, 2, reviewing a lesson is nil (zero) points.
So, as a compromise, my new plan is to do three reviews and end with a whole repeated lesson. This marks the last lesson by it's position and gives it the faint shading that indicates the last lesson completed and gives you a few extra points.
Reviews do count towards your "streak" by the way. If that is important to you