Sata splitter like USB hub



No.
At best, you'd be able to access one drive at a time.
Doubtful this would even work.
 
Simple answer, you cannot split SATA up like that. That looks to be a SAS breakout cable that supports multiple drives. In the server world it is very common to connect lots of drives to one port, but those are usually special RAID or SAS cards.

If you need to add drives, look into a PCI Express SATA card.