Can confirm that the BreakOutFloatXComponents and MakeFloatX nodes don’t directly show up in the search as before. However, there is a simple workaround for the time being: You can search for the MaterialFunctionCall node and select them from the Material Function dropdown in the Details panel.
It’s infuriating to me too - you can search for “break out float 2 components” in the engine content, open the material function and make sure “expose to library” is checked (click in the empty space of the material function editor to see that option in the left Details panel)
It will now be accessible on right click like before