After going to a previous lesson in the track I am unable to click on the circles to view the videos.

Hey Artur,

You're able to use the navigation bar at the top of every CC, video, and quiz to move to the next task. You'll see filled and empty white nodes (on the left and right, respectively, assuming you’re not on the first or last task of the stage) of your current task. Simply click the empty node to the right of your current position (indicated by your avatar in the middle of the node) to skip the current task.

You can also head into the library or the track your course is part of (where applicable) and then manually navigate to the section and video you wish to review. e.g.

teamtreehouse.com/library --> How to Make a Website --> Beginning HTML and CSS --> ^ 6 Steps (drop down menu) --> Add Style to the Page

This is not correct If I go to a previous course in the track (for instance jQuery Basics which I did months ago) I can no longer click on any of the circles. They are all filled in and none have allow me to click on them .
After double checking I did notice there is a course overview on the bottom and it looks like that might work, I don't remember those being there before but it will work.