Search datasets by name, or search inside the members?

Typing in the explorer hides datasets. I actually wanted to find a string inside a copybook. What is the difference?

Typing filters by name. Press Enter for a content search, with regex and case options. On the mainframe there is also Search Within Dataset. Right-click to mark My Maps or My Copybooks so screen and RPC actions can find them later. A name filter will not find a field that lives inside a member.