Hello. I have an android x86 virtual machine in virtualbox. Because the usual way to share folders between host and virtual machine hasn't worked for me, i had to use another method.
For that, you must have a samba server or a ftp server running on your host machine.
After that, go to virtual machine network settings and choose bridged adapter - not NAT.
Install es file manager from play store, go to network - lan or ftp - and scan for servers. You'll find the samba server or the ftp server who are running on the host machine. Connect to server, fill the authorization fileds with your credentials, and that's it!
(something more: i installed android because i needed snapseed to edit some images in a specific way but the application doesn't work on android virtual machine, and for that matter, nor facebook app. )