Complex sentence: Kevin Flynn (Jeff Bridges) is a software engineer formerly employed by ENCOM, having been fired by Ed Dillinger (David Warner) who stole several video games designed by Flynn to gain a series of promotions.
Split into simpler sentences: Kevin Flynn (Jeff Bridges) is a software engineer formerly employed by ENCOM. He had been fired by Ed Dillinger (David Warner) who had stolen several video games designed by Flynn to gain a series of promotions.