How to display search results in Bitrix on the same page, directly below the search form?

Question

1C-Bitrix

This is a search by numbers of certain documents and there can be only one result.

Answer 1

You don't need a search at all. Make an output component of your document.
Pass the filter by the document number field to the component.
You take the document number from the GET request, if this field is empty, then do not display anything. On the page, place a form with one field sending GET to the same page.
All.
Ask which step is not clear.