Para openSUSE Tumbleweed corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:michael-chang:bsc:1226497/openSUSE_Tumbleweed/home:michael-chang:bsc:1226497.repo
zypper refresh
zypper install grub2
Para openSUSE Factory corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:michael-chang:bsc:1226497/openSUSE_Factory/home:michael-chang:bsc:1226497.repo
zypper refresh
zypper install grub2
Para 15.6 corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:michael-chang:bsc:1226497/15.6/home:michael-chang:bsc:1226497.repo
zypper refresh
zypper install grub2