Here is the full solution for CraftConnections Day 52. Each group is shown with its difficulty colour and a redundant shape, so it stays readable if you are colour blind.
Classic — Day 52
● Axes Golden Axe · Stone Axe · Iron Axe · Wooden Axe
▲ Leaves Dark Oak Leaves · Spruce Leaves · Birch Leaves · Azalea Leaves
◆ Ways to get around Chorus Fruit · Activator Rail · Elytra · Oak Boat