If I understand the question properly you are looking for a USB hub wich connects to the computer through Bluetooh instead of using a cable, am I right?

In that case such a thing does not exists because Bluetooth is a very slow protocol and would not be USB compliant, not only because of the speed but because of the lattency, causing devices to disconnect intermitently.

I think it would be easier to a good bluetooth adapter with a bluetooth Keyboard and mouse.