Periscope is now organized with what are called 'views'. This has replaced 'tabs' in the earlier revisions of Periscope. Views are context sensitive, meaning they will only be displayed depending on what context level they were assigned.
Views can be added or modified by accessing the settings menu in the top right corner of the window.
While in the settings configuration, select the bottom icon to access the views. This will show you all the views that are currently set up, what their id is and the context they are associated with.
The Views main setting page is broken into 4 columns:
When Creating a view, click the 'Add' button at the bottom of the view pane. You're given a choice of 7 different view types, as seen below.
Once you select the view you'd like to add, give it a name, a unique icon, and most importantly a target designation for context.