Not sure if this helps or not but iff are using the desktop version of BS on the menu to the left of the main window are search starting options. Search All will search all of your local folders. When you type in a search term use can use multiple terms separated by a comma. So if you made an IPA with a particular yeast last year and want to find it among the many IPA's you've made since just search IPA, WLP001.
What displays is all recipes containing either IPA or WLP001 so if you want to see only those recipes that have both IPA and WLP001 use the drop down menu in the search tool and select "Match recipes containing all listed terms".
Thanks for the reply and, yes; I largely agree but for the cloud search.
I am indeed using BS3 Desktop, v 3.0.8. This is my folder view to which you refer:

There are also search starting options in the left side menu for Cloud and Cloud Search. I believe one searches your cloud recipes and the other searches the entire cloud database held at beersmithrecipes.com.
The Local Search works just fine (as I now know!). So a local search for S-04 yeast reveals these results...

The "Cloud" level in the folder list view opens the top level view of my folders in the RHS pane but no search criteria are available: the search bar there only searches the Names in that view, without searching subfolders.

But the Cloud Search seems to provide me with no options to search
my cloud folders...

...and returns only those cloud entries where the search term appears in the header/title/name of the beer across the whole of the cloud repository.