/proc/thread-self/root/proc/self
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 /.
11:perf_event:/10:devices:/9:cpu,cpuacct:/8:net_cls,net_prio:/7:hugetlb:/6:cpuset:/5:freezer:/4:memory:/3:pids:/2:blkio:/1:name=systemd:/