Search within Selection in Vim
\%V is a useful atom (TIL it's called an atom - and there are a lot of them, see :h pattern-atoms) that can be used to match inside a Visual selection.
Say you have a large file open and want to search for something only within a single area of text, like a method. You can visually select that block of text, enter command mode with :, and prefix the search with \%V to scope the search so that you only get matches inside the selection:
:'<,'>/\%Vsearch_text
You can also use \%V to search and replace.