Multiple energy-release processes in filament eruptions have been observed and are thought to be important to understand the detailed mechanism of filament eruptions. Here, we present a new observation of two distinct energy-release processes in a confined (failed) filament eruption. The first process is accompanied by the catastrophic imbalance of the filament system, just as many other filament eruptions. Intriguingly, there is another energy-release process in the upside of the filament system following the first process. Both processes started from a preceding increase of plasma velocity, and expanded from some small fragmented dynamic regions, where the plasma is heated to a high temperature (up to 6 MK for mean temperature). All of these provide us with a detailed record of energy-release processes within a confined filament eruption, and a direct evidence that a chain reaction of energy release can be triggered in the overlying magnetic arches of an entwined filament system by its eruption, even if it is strongly confined.