First, there is no original file in the case of hard links; all hard links are equal.
However, hard links aren’t involved here. Your problem arises because of a symlink, the bin symlink which points to usr/bin. To find all the paths in which bash is available, you need to tell find to follow symlinks, using the -L option:
$ find -L / -xdev -samefile /usr/bin/bash 2>/dev/null
/usr/bin/rbash
/usr/bin/bash
/bin/rbash
/bin/bash
I’m using -xdev here because I know your system is installed on a single file system; this avoids descending into /dev, /proc, /run, /sys etc.