Here is the full solution for CraftConnections Day 27. Each group is shown with its difficulty colour and a redundant shape, so it stays readable if you are colour blind.
Classic — Day 27
● Axes Golden Axe · Netherite Axe · Iron Axe · Diamond Axe
▲ Wool White Wool · Cyan Wool · Brown Wool · Lime Wool
◆ Ways to get around Minecart · Elytra · Chorus Fruit · Rail
★ The ender dragon cannot break these Iron Bars · End Stone · Crying Obsidian · Respawn Anchor
No-overlap — Day 27
● Axes Diamond Axe · Golden Axe · Stone Axe · Wooden Axe
▲ Farmer villagers plant these Wheat Seeds · Pitcher Pod · Beetroot Seeds · Torchflower Seeds
◆ Only found in the End Chorus Flower · End Stone Bricks · Dragon Egg · Dragon's Breath
★ These only stack to 16 Blue Egg · Egg · Brown Egg · Armor Stand