Is There a Supermassive Black Hole in the Milky Way?

If in any of the mergers at the Milky Way had that we had another supermassive black hole that was ejected. I wonder what percentage of the intergalactic stars were formed intergalactically by things like that versus just ejected from galaxies. Well, they couldn't get too far away because if once you're outside the CGM though, then there wouldn't probably wouldn't be enough of the gas available to cause a wake.