I think though, that at least in Polish, the "naród" includes the diaspora, or at least in the minds of some people it does, but definitely not everyone.
Well, in Polish the 'naród/nation' includes everyone that self-identify as being Polish. Obviously some Chinese in China declaring it out of the blue and on a whim, wouldn't be recognized as such but any other person with some credible reason would. Look for example on dolnoslask I'm pretty sure he sounds foreign but also I'm sure he is accepted as Polish.
To a Polish person a concept of nation and nationhood has less to do with a formal/legal requirements. Much more to do with concept of an eternal, transcend even on some level, bravehood of the cultural and historical identity that shape and define Polish people for what they are. As this song/poem goes - 'we are the Polish people the Royal line of Piast'.
Of course to be recognized as Polish one need to be able to speak Polish at least some. Although is not always a must. Once need to have a good explanation though.
Now and then you have some kid like snotty come up with this notion of blood, ethnicity, DNA, passport or whatnot. In fact that notion of ethnicity was never prevalent or some time in the past stopped to be important. Either because it was taken for granted or because concept of a nation had been created by the Polish gentry/nobles that had been rather mixed ethnically.
Once of the prominent people who stared the national democracy movement with Roman Dmowski has written - To the Polish nation belong polonised* (*the acquisition of the Polish culture and language) Germans, Tatars, Armenians, Gypsies, Jews if they live to the common idea of Poland.
A Black or a red Indian can became Polish, if he will take as his own a spiritual heritage of the Polish nation (well ..maf people?), from its literature, art, policies, customs, and if he vows to unbendingly work for the common good and prosperity of the Polish people.
It's also clear that Rzeczpospolita refers to the state (and not the nation), I think?
Rzeczpospolita i.e. The Republic refers to the state. All people with a Polish passport are citizens of the Republic but not all citizens belong to the Polish nation. That what it means in Polish. If anyone tell you different Delph it means that either they're not Polish or they are lefties trying to conform to the general trend in the west or just to adjust meaning to be 100% PC.
"Napoleon complex" is a term describing a theoretical condition occurring in people of short stature.
Funny if you think about it. After all Napoleon contrary to the British propaganda - fake news - wasn't actually a person of short stature.