Open Folder Tool
This tool will open Windows Explorer to the folder where the project file is located. If the active project is workset enabled the folder where the central file is located will be opened.
For Revit 2012 and up only: If a family is selected when the tool is executed, the folder where that family was loaded from will be opened. If a linked DWG is selected when the tool is executed, the folder where that linked file resides is opened.