I’m not entirely sure what you’re trying to do, but hopefully this will answer your question.
The left arrow has always selected the parent object, if there is such a thing. (In the case of a folder, there usually is.)
If you made a mistake typing you can use Delete to either wipe out the results and search again, or remove one character at a time. (This is based on a setting in Preferences → Extras.) This should work with the entire catalog, or within a smaller search like a folder you’ve navigated into.
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Rob McBroom