When editing items in batch from a bib record, you see a regular search box at the top of the screen. When editing individual items, you see a cataloging search. We should see a normal search for both.
I believe this is because one is using the cataloging module default and the other is using the tools default. I am not sure if there is a great solution here - it makes sense for me to have the cataloging search above the items form.
This is still true and now it's turned into a bug too: We have moved the tools to cataloguing, but haven't switched over the search bar apparently.