Today, through the virtualbox, I decided to share a folder on a computer that can share files or folders of data over a Local Area Network (LAN).
What I did was right click on my Computer on the virtualbox and go to Map Network Drive ...
Once a new Map Network Drive window pops up, it will ask you to choose a drive letter. There will be a drop down list that will show you which drives are available. You might notice that if you already have mapped drives, they will be indicated by a shared folder name that is seen inside the drop down list corresponding to the drive letter.
Now you selected the folder to map from the drop down list or by it's path \\server\share\
I had to use the path because it didn't show up on a drop down list. But once I did that, I was able to connect to the network shared folder no problem.