I was wondering the same, finally solved it!
First make a directory in /mnt;
sudo mkdir /mnt/Mp3
Then mount remote directory to your newly created /mnt/Mp3;
sudo mount -t cifs //192.168.0.XXX/SHARED/DIRECTORY/Mp3 /mnt/Mp3 -o username=YOURUSERNAME,passwd=YOURPASSWORD,noexec
Well, you need to know the IP address as well as username and password on the remote machine. That's it.
Now add your /mnt/Mp3 to Clementine's library and enjoy!...
EDIT: If you'd like to mount the shared directory everytime your machine boots, you need to add it to /etc/fstab list;
sudo nano /etc/fstab
add this to your list;
//192.168.0.XXX/SHARED/DIRECTORY/Mp3 /mnt/Mp3 cifs username=YOURUSERNAME,passwd=YOURPASSWORD,noexec 0 0