The Copy function is only available within the same ITP/MDK Repository. You can use the Copy (and Paste) function from the context menu of the object, or by using the default keyboard shortcuts i.e., Ctrl+C and Ctrl+V. For Projects also a Duplicate functionality is available. The Import/Export function can be used to copy objects or projects to another ITP/MDK Repository.
When an object is copied to a location where an object with the same name already exists, it is renamed after prompting the user. For Field Sets this happens if another Field Set with the same name exists somewhere in the project.