To reach this Chest in the Western Ascent of the Clock Tower, you must first acquire the Smash ability by beating Talos at the bottom of the Clock Tower.

Next, use it on the first switch to gain access to two blocks that can be broken with Smash. Use it on the leftmost block first to gain height to smash the block on the right.

Now activate the middle switch then the left switch to gain access to the chest.