virtualbox.org

I have successfully shared the host windows to ubuntu guest os but now I would like to share my guest os to my host windows.

If you have shared a windows folder from host to guest, now you can copy any file to that shared folder at your guest and use it in the host.

I mean, the shared folder si bi-directional.

PS: If you want to share a local folder of linux, install Samba and configure it.

GA shared folders are designed to provide a quick and simple way to share a host folder with the guest. If you want something else then Google for how to configure a normal network share.