Reverse Neopixel direction

[Scooby7274]

I have a chase effect that I want to run backwards so I get a forward and back effect. In Led effects simulator,I can get the reverse effect by adding a negative,but how do I add it to the effect? Do I add another chase effect under layers?

layers:
chase 0.70 1.00 top (0.0,0.6,0.2)