Dear Tzungkuen,

t> "Eva.m piyo puthu attaa paresa.m
t> Tasmaa na hi.mse paramattakaamo"ti

t> I don't know how to analyze exactly the 'attakaamo'. Can Nominative
t> be adverb?

The Nominative here is rather a noun: one who loves himself.

With Metta,

Dimitry