The default behavior for opening the Hierarchy view is to replace the Hierarchy view that is already open in the perspective. If there are no open Hierarchy views, one is opened automatically.
Sometimes, it is useful to look at or work with several type hierarchies in different perspectives. This can be achieved by changing a workbench preference.
Using the Hierarchy view
Changing new type hierarchy defaults
Opening a type hierarchy on a Java element
Opening a type hierarchy on the current text selection
Opening a type hierarchy in the workbench
Views and editors
Type Hierarchy view
Java Base preference page