Breaking apart or slicing layers in After Effects is easy enough, although it can be cumbersome and repetitive. There are third party tools that will let you slice any layer in Ae easily with non-destructive ways like “Slice It Up”, for example!
Another tool that can be helpful for those who work with a large number of Ae layers is the HUD Toolkit. This script started as way to speed up creating user interface and fake-UI animations in Ae, but it really comes into its own if you find yourself duplicating shapes often or need quick access between different types of objects from one document window – all without having open individual documents on your computer!
Some people might find the process of making layers react as desired a hassle.
Voxyde shows a technique he recently came up that will slice any layer in After Effects easily. HUD Toolkit can easily cut up any layer, and with one click you get pieces of your animation set for use on other layers or projects!