When you manually hide items using the Model Tree or create asynchronous items, such items are automatically added to a layer called Hidden Items, if it already exists. If it does not exist, a new layer called Hidden Items is automatically created and the hidden items are added to it. This layer is always created at the top in the Layer Tree list.

You can select any item in the Hidden Items layer and perform the Copy Item, Cut Item, or Paste Item operations using the shortcut menu to add or remove items from this layer. When you unhide items using Unhide All, all the manually hidden items that are listed under the Hidden Items layer are removed and displayed on the graphics screen.