It depends on the rocker.
If it’s a Crane or DC/MP rocker the oil goes into the shaft and then it gets to the rocker. There is a hole in the rocker and oil squirts out that hole onto the adjuster and hopefully into the cup.
If it is a rocker like PRW it oils the same until you get to the adjuster. Those rockers use a hole in the adjuster and it oils backwards from your example.
In other words, rather than going up through the pushrod and through the adjuster to the rocker, the oil goes into the shaft, out of the shaft to the rocker and then out a hole in the rocker that feeds the adjuster.
So the PRW rocker oils backwards of your example.