Currently the only way to select Standalone parts is from the ribbon button:
Mark Loose Parts (_AstM4CommStandaloneParts)
However, this marks the standalone parts in the whole model (even if you have a selection of objects), which is very inconvenient when you are working with part of the model and I feel is a very large oversight in the functionality of the software.
1. I want this function to work on the whole model if nothing is selected or just on the currently selected objects if you have a selection.
2. I also want the "Search and mark objects" tool (which is also used for Queries) to have an option for standalone parts (or to exclude standalone parts).