Sets how to apply an effect in an Effect Stack 2D:

• Chained applies the effect to the result of the previous effect, to the combined result of a sequence of layered effects, or to the node content. The next effect uses as its input the result of this effect.
• Layered applies the effect to the result of a previous chained effect or to the node content. A sequence of layered effects are combined on top of each other in layers.

This property has no impact on the Mask Effect 2D and Blur Effect 2D effects, which always use the Chained mode.