The first chance you have to do this is in Tribalstack Tropics. In order to expand the world, you first need to find 3 Pagies in that world.
Once you have found the Pagies and have decided that you're ready to expand the world, head back to the beginning of the level and exit to Hivory Towers. Once there, you will have a conversation explaining how to expand the world. After the conversation, just stand on the pedestal and hit
to expand, unlocking this trophy.
This will also give you credit towards:
and