When viewing the challenge library, every single challenge that is within the team and Qualified library is shown by default. This is great for browsing what is available, but it can make things hard to manage if you are working on building out new sets of challenges. You might be working on a bunch of draft challenges that will go into an assessment, are a part of a course, or specific to a role that you are going to be hiring for.
There is an easy solution, labels. Labels can be used for many purposes and are available to be applied to Candidate, Assessment and Challenge records. For challenges, one of the best uses for them is to define different workspaces. Then you can easily filter your challenges by the workspace label and only view the challenges that are relevant to that development effort.
You can add one or more labels to a challenge simply by editing it. To filter, use the "Labels" filter within the challenge list sidebar. Try adding a workspace such as "Jane's Workspace" or "Front-end Developer Role".