This but also:

Files already had a search button, but now, you get a new search icon in the top-left corner of the window, and the older search icon gets a new look. gnome 46 global search button screenshot

You can also head to search settings to adjust how you want to look for things.

The new search button lets you search across the system. However, the older one (with a new look) lets you search inside the current folder/directory you are in.

Is really new peaks of not-a-new-feature