Malezas literally translates to "weeds." It's an interesting word choice because it's not commonly found in song lyrics, especially in a romantic context.
In this song, Kalimba uses "malezas" metaphorically to describe the tangled, perhaps problematic, aspects of a past relationship. He sings, "ya no entiendes tus malezas solo quieres buscarme" (you no longer understand your weeds, you just want to look for me), implying that the other person's issues or complications are now their own to deal with, and he's moved on to a "new world without you."
Kalimba opens with the breakup already decided: "Se te acabó la primavera" ("Your springtime is over") — the relationship's warmth has run out, and she's the one walking away. He doesn't beg. He answers her exit with a flat refusal to be wrecked by it: "Sabes que yo soy quien pudo amarte" ("You know I'm the one who could have loved you"), a line that reads less like regret than a closing argument.
The chorus turns the breakup into an eviction notice. "Búscate otra historia que arruinar" ("Go find another story to ruin") hands the blame back to her outright, and "Porque he inventado un nuevo mundo sin ti" ("Because I've invented a new world without you") is the title's whole idea in one line — not healing, exactly, but a deliberate act of building somewhere she isn't. By the second verse the same opening image repeats, her springtime ending again, as if the song is daring her to leave a second time now that he's already gone.