The Collapsible Dashboard Sidebar Add-on for JIRA, as its name suggests, makes the Favorite Dashboards sidebar collapsible. This allows the users having more than one favorite dashboard to easily free up screen real estate without losing the possibility of switching between dashboards in one click. 

• You can hide the Favorites Dashboards Sidebar simply by clicking the  icon at the top right of the panel. The sidebar collapses as shows below:
  

• In order to have access to the dashboards list again, move your mouse over the left window edge. The Favorite Dashboards sidebar will appear on the screen.
  

• To dock the Favorite Dashboards sidebar, click the  icon at the top right of the panel. The dashboards list will always be visible.
  

Useful links

• Collapsible Dashboard Sidebar Add-on Home Page
• Listing on the Atlassian Marketplace