Tracking recently changed events?

No doubt many people are using Node Red for home automation. That's how I learned about Node Red in the first place, from Hubitat's forums. Though I believe Hubitat's node was only recently created. And I have most definitely searched the forums for help on a number of things I wanted to accomplish. The documents embedded with each node is also very helpful! I've probably converted 90% of my hubitat rules to node red flows and am very happy with how well they work. They were very basic event driven flows though. I.e. button controllers, lighting schedules, alexa announcements.

Everyone on this thread has been extremely helpful. And even by the first two replies I was able to get a working flow that made sense to me.

My searches for what I was particularly looking for did not yield too many examples. Maybe 2 out of 50? I attribute this to three things. a) Used the wrong search terms. b) Confused node red's "low-code programming" with "no code" programming. I skipped over anything involving custom functions though this is probably what I'm going to use, and lastly c) skipping over posts I thought were irrelevant to me (I'm talking about you openhab post! Rookie mistake!)

As an aside, the openhab post showed a visual representation of switches in series that @robmak was talking about that I just couldn't get. What I was doing was wiring up device -> switch -> device -> switch. -> command. The openhab example shows switches literally wired together, but the switch input/output were based on variables.