This is straight from the help menu.....
Saving Views to an External Project
- Select a view in the Project Browser.
- Right-click the view name, and click Save to New File.
- Enter a new name for the Revit file.
Inserting a Drafting View from Another Project
- Click Insert tab Import panel Insert from File drop-down Insert Views from File.
- In the Open dialog, select a project file, and click Open.
From the list, select an option for views to display.
- Select the views to insert, and click OK.