Exploradora is guerrilla rank 3 in Libertad. It unlocks more weapons and gear and, most notably, lets you buy the Furioso Supremo from Juan for Depleted Uranium.
Your guerrilla rank rises as you earn XP across Yara. Each new rank opens a new batch of weapons and gear for purchase, and some items say right in their unlock text which rank you need. The game shows either the feminine or masculine form of each title.
Furioso is the first extra Supremo many players buy, and it needs this rank. Save some Depleted Uranium so you can grab it as soon as you rank up.
Rank 1: Machetera
Libertad rank 1. Weapons and gear marked for Rank 1 can be bought from Juan and his Arms Dealers.
Rank 5: Cabo
Libertad rank 5. Weapons and gear marked for Rank 5 can be bought from Juan and his Arms Dealers.
Zona Medicina
Releases a healing cloud that doubles health regeneration for you and nearby allies. With a full charge it can revive you.