This quote says it:
> The labor market continues to be out of balance, with demand for workers substantially exceeding the supply of available workers. The labor force participation rate showed a welcome uptick in August but is little changed since the beginning of the year. FOMC participants expect supply and demand conditions in the labor market to come into better balance over time, easing the upward pressure on wages and prices. The median projection in the SEP for the unemployment rate rises to 4.4 percent at the end of next year, ½ percentage point higher than in the June projections
He's expecting the act of raising interest rates to increase unemployment to 4.4%. He's doing this to bring balance to supply and demand for labor, to ease upward pressure on prices.
He is also asked directly when he will know when to stop:
> So I will answer—I will answer your question directly, but I want to start here today by saying that my main message has not changed at all since Jackson Hole. The FOMC is strongly resolved to bring inflation down to 2 percent, and we will keep at it until the job is done. So the way we’re thinking about this is, the overarching focus of the Committee is getting inflation back down to 2 percent. To accomplish that, we think we’ll need to do two things, in particular: to achieve a period of growth below trend; and also some softening in labor market conditions to foster a better balance between demand and supply in the labor market.
He directly says he's waiting to see softening of the labor market before stopping the rate hikes.