cgroupv1 has a hierarchy per-resource, for example:
ls /sys/fs/cgroup
returns:
blkio cpu,cpuacct freezer net_cls perf_event systemd cpu cpuset hugetlb net_cls,net_prio pids unified cpuacct devices memory net_prio rdma
Each resource hierarchy contains cgroups for this resource:
find /sys/fs/cgroup/pids -type d
returns:
/sys/fs/cgroup/pids /sys/fs/cgroup/pids/docker /sys/fs/cgroup/pids/user.slice /sys/fs/cgroup/pids/system.slice /sys/fs/cgroup/pids/system.slice/irqbalance.service /sys/fs/cgroup/pids/system.slice/containerd.service /sys/fs/cgroup/pids/system.slice/systemd-networkd.service /sys/fs/cgroup/pids/system.slice/whoopsie.service /sys/fs/cgroup/pids/system.slice/cron.service /sys/fs/cgroup/pids/system.slice/avahi-daemon.service /sys/fs/cgroup/pids/system.slice/systemd-logind.service /sys/fs/cgroup/pids/machine.slice ...