lol, no :)

first of all, it only searches for occurrences in already installed packages and is more or less a grep -l xxx /var/lib/dpkg/info/*.list. So you can’t use it in order to determine which package to install, for that you use https://packages.debian.org or apt-file instead.

Secondly, what you search for isn’t relative to anything (wtf):

$ dpkg-query -S /etc/grub.d/                                  
fwupd, grub-common: /etc/grub.d