Is there any way to do a search across multiple Scrivener files at the same time?
Edit > Find > Project Search will search the whole project.
Or do you mean search multiple Scrivener projects, rather than multiple files within the project? In that case you would have to use Spotlight, unless I’m very much mistaken. Or HoudahSpot, which has a better interface.
Or you can just use the toolbar search filed instead of going to Edit > Find > Project Search.
All the best,