Mieles is the plural of miel, meaning "honey." While miel is common, its plural form mieles is less frequently used, especially in this context.
In the song, the lyric "Voy en busca de mieles, voy de flor en flor" (I go in search of honeys, I go from flower to flower) uses mieles metaphorically. It refers to seeking out new romantic interests or pleasures, much like a bee goes from flower to flower collecting nectar. This poetic usage makes it an interesting and evocative word choice.
Los Dos Carnales bring us a song about the bitter aftermath of a breakup. Our singer is really going through it, telling us, "Ya no creo en el amor" [I no longer believe in love] and "Desde que tú te fuiste ya no sé quién soy" [Since you left, I don't know who I am anymore]. It sounds like this person really pulled the rug out from under him, leaving him feeling lost and alone.
He's pretty blunt about how much this hurt, saying, "Me pegaste muy duro aquí en el corazón" [You hit me very hard here in the heart] and "Me dejaste en lo oscuro y me apagaste el sol" [You left me in the dark and turned off my sun]. Now, he's just drifting, going "de flor en flor" [from flower to flower], accompanied only by "la soledad y el alcohol" [loneliness and alcohol]. He declares, "Soy de todas y de nadie" [I belong to all and to no one], explaining that his feelings are just carried away by the wind. He's out on the streets, looking for memories of his lost love, and in the meantime, he's "dejando caricias en distintos cuerpos" [leaving caresses on different bodies]. It's a pretty raw look at how heartbreak can make someone feel completely disconnected and just wander through life.