From the Rich Filters App Configuration page, Jira administrators can enable/disable labs features. These are experimental app features which might suffer changes in the future. Please don’t hesitate to provide feedback if you find these features useful! This will allow us to take into account your feedback and also to notify you if changes are expected to happen in future releases.

Available Labs Features:

• Quick Filters Mode: Allow Rich Filter quick filters to be ORed together instead of ANDed
  If this feature is enabled, a new advanced setting will be available per Rich Filter. For each individual Rich Filter you can decide if the quick filters should be ANDed together when used on dashboards (the current default behavior), or if these should be ORed instead of ANDed. This would allow the user to select the reunion of the issues satisfying the quick filters instead of the intersection.
  
  

  The rich filter administrator can chose between the Intersection (default) and the Union quick filters mode.