Hello
There are many ways and characteristics to describe tobacco from different countries. I like focusing on the texture and main flavors. Of course tobacco can be very different from the same country depending on variety, harvest time, specific region etc...
However I find in general Nicaraguan cigars to have a somewhat gritty earthy texture. Flavors have a wide range but I mostly get notes of pepper earth and sometimes cocoa/chocolate. I've also had very woody and leathery flavors and even some fruit here and there. But overall when I think Nicaragua I think gritty pepper and earth.
I find Dominican cigars to be less gritty but still earthy. It's a different type of earth more musty or damp. I also get a lot of nutty flavors from Dominican tobacco but there is still pepper and leather to be had in most Dominicans.
From the cuban cigars I've had the tobacco seems to lean more vegetal. You'll pick up a lot more grass/hay type flavors. One thing I've noticed is there is never any gritty earth to be had in cubans. It's hard to describe but they almost seem cleaner so to speak with a slightly creamy texture.
I can't say I've ever had a puro of another country but I know Honduran tobacco is said to be similar to Nicaraguan because of the close proximity.