If both the Bose and the TV have ARC (audio return channel) then you have to connect the Bose to the HDMI input labeled ARC and turn that function on in the TV and maybe Bose.
If one or both doesn't have ARC then you will have connect as Alabalcho suggests.
You might need an DAC to convert digital to analog audio if the Bose doesn't have digital input or a converter to go from optical to coax or vice versa if they both have digital but not the same kind.