When there is a large number of items displayed in a search filter, it can be difficult for you to focus on the information you are interested in, so Mainframe Explorer enables you to hide items (data sets and/or data set members) from view.
By default, all accessible items that match the search filter are displayed; this is referred to as the Active Catalog Item view. You can hide items from this view, which then appear in the Hidden Catalog Item view.
Hiding items does not change them in any way, and you can restore items from the Hidden Catalog Item view back to the Active Catalog Item view at any time.