On the left, the four lines are the historical policy rates from G4 central banks (the U.S., Eurozone, UK and Japan). In the case of the UK, Japan and euro area, policy rates have remained low for much of the post-global financial crisis era. The U.S., UK and eurozone have been raising rates as they are facing considerable inflation pressure.
On the right, the four lines show market expectation of where policy rates would be in the future. Investor expectations in 2022 has reflected the hawkish sentiments with the U.S. Federal Reserve, the Bank of England and the European Central Bank. The drop in expectations in February/March '23 reflects the view that the banking crisis might cause a shift in policy, but investors generally expect policy rates to stay high. The Bank of Japan, however, is still a ways off from any meaningful tightening.