In Sunshine theme, you can setup sliding panel feature. On click of a button, you should see a sliding widget displaying your custom content. You can add different type of content in this special widget area.
Setup Sliding Panel Right widget
1. In WordPress Dashboard, go to Appearance > Widgets. Now drag and drop “Simple Pro sliding panel right” widget to “Nav Extras” widget area.
2. Enter title in the widget. Whatever title is entered, it will display as link text on button to trigger the sliding panel right widget.
3. Now add contents in the sliding panel by dragging various widgets to Sliding Panel Right widget area. You can display: enews box, featured posts, search box or text box in this area.