Isolate Select recreates the isolate-select behaviour familiar from Maya and 3ds Max inside Blender. It gives the viewport a local view: an individual display state separate from an object's non-display or viewport display state. You can isolate a display temporarily without changing the display state stored on the data, which is useful when you want to edit a specific object inside a complicated scene.
The local view can be repeated any number of times, and an isolation level lets you step up or down through nested isolations. You can undo the separated display state the add-on creates, and return to the global view when the isolation level is low enough. When isolating, the add-on can always include lights and objects from a specified collection.
Display options keep useful context visible. Display Lights keeps lights shown and lets you work in Render View on Eevee without changing the appearance, Display Image empty keeps a reference image displayed, and Display Collection keeps a chosen collection visible along with its child collections. In mesh edit mode, Hide unselected mesh hides non-selected areas so only the fully selected part is shown.