Work Through Lists with Ease Using Split View for Standard Navigation
Where: This change applies to Lightning Experience in Group, Essentials, Professional, Enterprise, Performance, Unlimited, and Developer editions.
When: This functionality is available on a rolling basis during the Summer ’20 release.
How: To access split view, select Split View from the Display As dropdown menu. If you select split view for an object, that object automatically loads in split view until you change its Display As view.
In split view, open a record to see it next to your list. To collapse the list view , click (1). Click to expand the list again.