/proc/self/task/15/root/proc
This explorer reads the filesystem of the server it runs on, so /workspace/user isn't present here. Browsing and the terminal still work against this server's own disk from /.
#subsys_name hierarchy num_cgroups enabledcpuset 9 1 1cpu 4 52 1cpuacct 4 52 1blkio 7 49 1memory 2 66 1devices 8 49 1freezer 3 4 1net_cls 10 1 1perf_event 11 1 1net_prio 10 1 1hugetlb 5 1 1pids 6 49 1