As pointed out here,
type-ahead find has been removed in favour of
full text search.
However, it is possible to make
full text search behave more like
type-ahead find. Simply open the Nautilus Preferences, click the Search and Preview tab, and make the following adjustments under the "Search" heading:
- Search in subfolders: Never
- Full text search: do not set as default
Now typing letters in Nautilus will only search files by their names, not by their contents, and only for files in the current directory, not subdirectories. Unfortunately, this also affects the results you see when you do a Ctrl+F search.
I would just like to add my voice to the many who think that disabling
type-ahead find was a mistake, and the fact that it is not even available as an optional feature is an incomprehensibly poor decision on the part of the Nautilus developers, especially given that
full text search was always available via Ctrl+F for those that wanted it. I hope Ubuntu switch back to using a patched version of Nautilus for 18.04.