I inadvertently deleted the global community peer-to-peer search bar off of my community home page. Now I have a blank rectangle where I want the search bar. I can't figure out how to get it back.
Assuming you are using a Lighting Template, such as Customer Service (Napili) then it may be caused by one of the following.
If the css from the theme includes
If the entire header region is missing then it could be a setting like these options from either the theme settings or the Theme tab in the Settings, see the images below.