Two tiered greens are a very common feature on golf courses. A two tiered green simply has two different levels of putting surface that are connected with a slope between them.
This makes the green much more challenging when out playing, especially if your golf ball has finished on one tier and the hole is on the other.
The main concept to realize when facing a two tiered putting green and a putt from one tier on to the other, is that the distance that the ball needs to travel is actually further than it appears. If you take into account the vertical slope that connects the two tiers and you stretched this out horizontally, the length of the putt would be much longer if you measured the total ground for the ball to roll over, than if you measured the distance, as it appears, directly from the ball to the hole, without taking the length of the slope in to consideration, so measuring directly as the crow flies.
Once you take this into consideration it will become easier to get the putt on to the tier with the hole and much closer to the hole. If you are on the lower tier, putting up the connecting slope to the higher tier, you will need to hit the ball firm enough to get it all the way up the connecting slope and on to the top tier. Break the putt into three sections. The first section is the lower tier area from the ball to the slope. Read the green by crouching down behind the ball directly in line with the ball and the hole. Look at the surface of the green, notice the slopes. Now look at the second section of the putt, the slope. Look at how much gradient there is to the slope and how firm you will need to strike the putt to get it up the slope, to the top level. The final section of the putt is the upper tier. Again notice the slopes, how the putt will break, etc. Break the putt down into these three sections if you are putting down on to the lower tier as well.
Now you know how the ball will react through each section of the putt, work out where to initially aim the ball so that it finishes that section in the correct position to begin the next section of the putt. But now it is all down to distance control.
Imagine the putt that you are facing is actually straight. You are on the upper tier working on getting the ball to finish close to the hole on the lower tier. As a general rule of thumb, hit the putt so that the ball reaches the top of the slope at a “trickle” pace. Get the ball to the edge of the slope so that gravity can then bring the ball down the slope to the tier below. The speed that you want the ball rolling at down the slope will obviously depend on how far the hole is away from the bottom of the slope. If the hole is really close to the bottom of the slope then you want the ball rolling very slowly as it approaches the slope, however, if the hole is some distance from the bottom of the slope, you will need the ball rolling faster down to the lower tier so that it rolls across the green, close to the hole on the bottom tier.
The opposite is true if you are putting up the slope. Hit the ball firm enough to get it to the upper tier, but if there is a lot of distance between the top of the slope and the hole, then you will obviously need to hit the putt much firmer than if the hole is close to the top of the slope.
Your priority though should be to get the ball on to the tier that the hole is on, otherwise if you are putting again from the same level tier, it is a wasted shot, so ensure the ball reaches the other tier so that you are playing your next putt from the tier that the hole is on.