niggling, picky, nitpicking on petty details
[adjective]

"Pietluttig" can be used to qualify a person nitpicking on petty details, AND to qualify the petty details this person is nitpicking on…

Related nouns are "pietluttigheid": petty detail, and "pietlut": nitpicker, which is more or less synonymous to "mierenneuker".

"Pietluttig" is also more or less synonymous to "kleinzielig": petty.

Examples:
– "Doe niet zo pietluttig over de kleur van de deur, dit is een prachtig huis!" 
("Don’t be so picky on the colour of the door, this is a beautiful house!")

– "Beetje pietluttig van je om te klagen over Franks gedrag, terwijl jij mij ook verveelt met je onzin." 
("You’re a bit of a nitpicker to complain about Frank’s behaviour, while you annoy me too with your nonsense.")

– "Het leven is een aaneenschakeling van pietluttigheden…" – "Ben je met het verkeerde been uit bed gestapt of zo?." 
("Life is a concatenation of petty details…"  – "Did you get up on the wrong side of the bed, or what?")

Related words:
– Kleinzielig: petty [adjective].
– Bekrompen: narrow minded [adjective].

Example:
– "Mensen zijn soms zo bekrompen…" – "Zeg dat wel."
("People are so narrow minded sometimes…" – "You can say that again.")

– Mierenneuker: nitpicker [noun] [de mierenneuker, de mierenneukers].
– Muggenzifter: nitpicker [noun] [de muggenzifter, de muggenzifters].