I've always been interested on the impact that re-unification has had on Germany, rather, the impact of the split. Did people like the split at the time/when they were unified? What was its impact?
(As far as I know) most nationalists identify themselves as "german", and not as east/west/south/however-german. But of course there are always a few people identifying themselve more as a bavarian, or are exspecially proud of being from a certain place in generall, but that's also not much different from any other country. Actually, many nationalists will claim that parts of today's France, Denmark, and exspecially Poland (and a few more areas) are part of "their" Germany, since huge regions there were taken away from Germany after WW II. Nowadays of course, nearly 70 years after the war, in these regions most people don't identify themselves as german at all anymore. So I would guess, most nationalists saw and see the reunification as one step back to the "old-time-germany"and therefore as one state. Seperation movements (mainly only occuring in Bavaria, but by far not as strong as for example in Scottland) wouldn't be called "nationalistic" either way, since they are "again the nation". Hope that answers your questions.
TL;DR Nationalists want "the one Germany", and therefore shouldn't identify as a certain "type" of german. But hey, these kind of people never appears to think very logical, so you never know...
To go more into the the identity of the average people; identifying with anything similar to nationalism is much less common then in other countries. So, you wouldn't say proudly "Oho, Im from the West!". But exspecially after the reunification, there sometimes occured slightly... Arrogance and denegotiation against each other, reflecting in terms like "Besserwessi". Still today, you may use the terms "Wessi" or "Ossi" for a person from the west or the east, respectively, but mostly only in a context of humor. The "Ost-West-integration" is still a big topic in today's politics, as for example the pensions, which are still slightly different between east and west. But beside some jokes there is basically no serious distinction between east and west Germans anymore in the people's mind; as far as not concerning politics or the economy.