If you have a lot of notebooks, organizing all your content is really important.
In PushMetrics, there are multiple ways to keep things in order:

Access the folder moving feature from the Sidebar or the Notebook Header

You will be faced with a simple folder selection screen to choose a destination for your Notebook.

On the notebook list views, you can add Tags to a notebook:

Tags can also be applied in the Notebook Header

You can filter your Notebook list views for various attributes like Tag , Name, Created at, Created by, Modified at, Modified by .
Multiple filter criteria can be combined to create useful filter selections, for example, you can only show notebooks with the tag Verified that have been updated in the last 10 days.

Once you are happy with your filter selection, you can save this list as a Saved View .

Saved Views then show up in the left sidebar and provide handy shortcuts:

Please note that Saved Views are currently shared workspace-wide, meaning everyone will see the same views.
Especially when used with dynamic filter criteria like Tags and relative date filters like less than X days ago this is a powerful tool for content curation.