systemd-cgls — Recursively show control group contents
systemd-cgls [OPTIONS...]  [CGROUP...] 
systemd-cgls recursively
                shows the contents of the selected Linux control group
                hierarchy in a tree. If arguments are specified shows
                all member processes of the specified control groups
                plus all their subgroups and their members. The
                control groups may either be specified by their full
                file paths or are assumed in the systemd control group
                hierarchy. If no argument is specified and the current
                working directory is beneath the control group mount
                point /sys/fs/cgroup shows the contents
                of the control group the working directory refers
                to. Otherwise the full systemd control group hierarchy
                is shown.