Is there no way in which one can access the host's filesystem from within a guest OS.

Libvirt's virt-manager GUI seems to indicate that there is, by virtue of the FileSystem Passthrough option as shown below

The scenario I typically have is a Linux Server on a ext4 file system, with a Windows 7 Guest OS running a KVM machine.

No matter what combination of options I choose, I can never "mount" the host drive in Windows to be able to transfer files from one to the other.  Both VMWare Player and Virtualbox have this capability, yet I find this sorely lacking in libvirt/virt-manager.  What do I need to do to make this work?

regards