PXE booted client, how to restore to directory?

My linux urbackup server (A) takes backups of a netbooted linux machine B

Now B has failed and I need to restore. How would I go about doing
so via urbackupclientctl i.e. restore the netbooted machine B into a directory on A
(if all permissions were intact I could just scp into the right directory)

Basically I would like to restore the machine B from the urbackupserver A to
a specific directory on my NFS server (which in this case also is A)

From a machine C calling e.g.
urbackupclientctl restore-start -b last -d root -m / -t /mnt/restore_to_here
would attempt to restore machine C and not B

urbackupclientctl restore-start -b last -d root -m / -t /mnt/restore_to_here -c B
does not work either

Please advice