How to hide Sub-component list?

I am having to work with a complex building model derived from Revit. There are a vast number of components in the building (as others have noted, in the conversion process Revit/Autocad Block Instances are converted to unique Components, which greatly inflates the component list). It makes it very difficult to find particular component I might need especially as a bug in the component window prevents using the scroll bars (the list snaps back to the top when the scroll bar is released). And bizarrely, there seems to be no way to search for a local component or even to jump to the first letter of the component name by typing it.
So I made the whole building a component, imagining that all the sub-compenents would be removed from the list (unless I ‘Expand’ it). But they are still there. Even after close and reopen…
Any ideas welcomed!!

First reaction is to say charge the client double as a penalty for using Revit. Great in the hands of an expert, but! Aside from that, Revit is quite good at organising stuff, so I generally just click on things that would likely be in the same grouping (family) and go from there, hoping that the author has segregated things appropriately.

The expand option is activated if you rightclick and choose to ‘Save as’ the component, first.