PlayUp Alpha ver. 0.9.5 (now available in the Download section) allows you to export nested groups & components to CryEngine2 with one important caveat: MIRRORED COMPONENTS/GROUPS ARE NOT YET SUPPORTED. CryEngine2 does not allow for negative scale values, which makes PlayUp's job a bit trickier. In the interim while a solution is being worked out, you can fix this by exploding the mirrored components and making them new components.