Yes, you do mean 3 levels of light - low, med., high? Was it the lamp and/or the type of light fixture? Maybe you only really need high and low?
Looking at the Northwood site, you have a "standard" pancake style light over the dinette table. I could be wrong and would have to searching, is that they are available with two switches in them so you can get high and low levels. I couldn't find any interior pics of your old truck camper.
What about contacting Lance to see what you can get now?
My suggestion would be to remove the pancake light and replace it with something else. I removed all of the pancake lights in our 2014 TT and replaced them with light fixtures from Kaper II. I can't seem to find a website of theirs with their RV lights on it. RV dealers have them on display I've noticed. I used one of their lights that is the same size as pancake lights and left no holes showing.
You could install some LED "puck" lights. I've installed 10 of them in our new TT. You can get them in various lumen ratings. These are very shallow and fit easily in many locations. A ceiling would be easy. You could install the quantity you want to get multi-level lighting and the lighting level you want. I bought ours on ebay and they are only about $10 each now.
If you want good lighting over your dinette table for task lighting (including reading), from a lighting design perspective, a light in the center of the table is not the best location. You'll get less glare and less annoying shadows if the lights are centered above the edges of the table on each side. You could for example, install one or two puck lights on each side of the table for high level lighting and replace the existing pancake light for low level.
You should be able to install light switches on the ceiling fairly easily. Personally, I can't stand having to reach up to a pancake light to switch them. I've added wall switches throughout our TT now. You *should* be able to fish low voltage wiring across the ceiling and down the adjacent side wall without too much difficulty.
I guess with the correct type of LED lights, you could also just use an LED dimmer.