To mount a directory from your "real" computer, the so-called host, in the file system of the VM, you can do the following:
Select the folder you want to share in Virtual Box (see screenshot). Select permanent, but NOT auto-mounting (screenshot).
Remember the name of the share (in my example, Desktop)
Within the VM, now create a folder where you want the content of your host folder to appear. For example, this could be:
mkdir /home/damian/myrealcomputer
Now, use the following line to mount the share (in my example, it is called Desktop) to that folder:
sudo mount -t vboxsf -o uid=$UID,gid=$(id -g) Desktop /home/damian/myrealcomputer/
To mount a directory from your "real" computer, the so-called host, in the file system of the VM, you can do the following: Select the folder you want to share in Virtual Box (see screenshot). Select permanent, but NOT auto-mounting (screenshot). Remember the name of the share (in my example, Desktop)
Within the VM, now create a folder where you want the content of your host folder to appear. For example, this could be:
mkdir /home/damian/myrealcomputer
Now, use the following line to mount the share (in my example, it is called Desktop) to that folder:
sudo mount -t vboxsf -o uid=$UID,gid=$(id -g) Desktop /home/damian/myrealcomputer/