The metronome is the single most useful piece of practice equipment a drummer owns. But how you set it changes what you're actually training. The same backbeat practiced three different ways with three different click placements becomes three different exercises.
Every quarter-note clicks. This is what you start with. The click is a wall you can lean on; every hit lands on or near a click, so feedback is immediate. It teaches your body that "in time" means "lined up with this signal." Use this for early coordination drills, new patterns, and any time the groove itself is the new material.
Now the click only happens twice per bar — on beats 2 and 4. Internally, this feels like the snare. Suddenly the click sounds like a high-hat or a backbeat instead of a metronome. You have to feel beats 1 and 3 yourself, between the clicks. This is the intermediate setting — most professional drummers practice here for groove work because it forces them to internalize the rest of the bar.
One click per bar. Now you have to hold tempo for three full beats with no signal at all, only meeting the click again on the downbeat. This reveals every micro-drift in your time. Advanced drummers practice this to extreme degrees — with the click on beat 1 of every second bar, every fourth bar, and so on. For now, one-click-per-bar is the goal.
You don't graduate from one setting to the next. They're three tools, not three levels. The rule of thumb: practice the new groove with click-on-every-beat; practice the old groove (the one already comfortable) with click-on-2-and-4 or click-on-1. The harder click setting is what you use once a pattern is reliable, to test whether your time is yours or whether it was the metronome's. As soon as the time wobbles, drop back to a denser click and rebuild.
The exercises notate the same basic backbeat three times. The "click" itself isn't drawn on the staff — your metronome provides it. The tip on each exercise tells you where to set the click. The drumming is identical; the practice context is what changes.