Stir together coconut milk, whole milk, and sweetened condensed milk in a heatproof drinking glass until smooth. Add several ice cubes to glass. Meanwhile, heat water in a kettle to 205°F. Place coffee in phin filter, and shake to level; gently drop gravity press on coffee grounds. Pour about 2 tablespoons hot water into phin filter to cover filter press by half an inch; let coffee bloom, 30 to 45 seconds. Add 6 tablespoons hot water to fill to top of phin, and let coffee drip through, about 5 minutes. Stir to combine, and serve immediately.