Ruining future profits for the sake of immediate gain.

Literal

Immediate [poss-の] profit [poss-の] for [purpose-ために] future [poss-の] profit [obj-を] ruin.

目前 ('before one's eyes, immediate') contrasts with 将来 ('future'). 台無しにする ('ruin, reduce to nothing') is an idiom — 台無し literally means 'no stand/platform,' i.e., the foundation is destroyed.