Root Refresh is a function that recognizes your currently opened assembly and displays it at the top of the cBOM and eBOM views with only its first level of items below it. There are no right-click functions available for any child items; they are shown for information purposes only.
The Root Refresh function is useful for loading and checking in very large assemblies and drawings of very large assemblies. Performing a full refresh followed by a check in may end up taking several minutes to complete.