For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:vlefebvre:branches:home:fbui:systemd:v260/openSUSE_Tumbleweed/home:vlefebvre:branches:home:fbui:systemd:v260.repo
zypper refresh
zypper install systemd
For openSUSE Factory run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:vlefebvre:branches:home:fbui:systemd:v260/openSUSE_Factory/home:vlefebvre:branches:home:fbui:systemd:v260.repo
zypper refresh
zypper install systemd