I will be following this thread. You question is a VERY TOUGH one. I know for me, I was able to find a couple of tiers on a practice green I spent some time on … it was a game saver… Going up a tier is less of a challenge… coming down is a bear, since you have to estimate roll out.
Here is what I do for putting up a tier. I read the green from the tier to the hole, and then from the location of the ball to the top of the tier. Since based on your location the upslope has an impact on the direction. This gives me the line I need to putt on.
Now we need the speed. When I am on the top tier I make a putting stroke that I think will be the amount needed to make the putt from where the top tier starts is to the hole. Then I go to my ball location and make another practice swing to gauge the amount of energy it takes to get the ball onto the top tier. Then I just let my mind combine those to strokes - amount of energy and stroke the ball. Your brain is powerful and I know this works… it just takes some practice and trust.
You can apply the same idea in reverse from putting down a tier. … both for the read and the energy. I get right to the top of the tier when it starts to drop off and determine, how far the ball will roll out, if I just barely get it over the edge… then… well you get the idea. Hope this helps.