He means "Find in files", I just tested it. And yes, for some (obnoxious) reason it shows tabs as #$09.
Except for leading tabs, leading tabs/spaces aren't shown. But a tab char in the middle of the line => screws up the search result.
Sorry, not aware of any options.
But I suggest to report it as a bug. After all, it makes it impossible to distinguish between a line containing a tab and a line containing the literal text #$09