sorry i not quite understand what did you mean: host system resources usage by Parallels environment or what?
This feature (monitoring system resources usage by VMs) will be presents in server Parallels product version. Currently you can receiving approximate statistics of resources usage by Parallels Desktop using your host system profiler (system monitor). In this case Parallels Desktop process host memory and CPU usage values are interesting you statistics. It almost equals system resources that guest OS using for it work. At guest OS you can also using corresponding system monitor to receive necessary statistics.
i'm quite sure not because feature of VMs system resources usage monitoring mostly approach to server product version when you as system admin for example want to collecting such statistics. At Parallels server this feature will be presents as part of client GUI either presents in public API for own purposes.