Individual Heightmap Imports with World Composition?

Hello,

I’m making a 3km x 3km open world level and I’m using world composition to do so. What I have made are 9 tiles (to arrange into a square shape) and I have 9 individual heightmaps I would like to upload to the tiles. However I can’t seem to figure out how to do this? Is it possible? If so, how can I do this? If it isn’t possible, how would you recommend I go about doing this? Thank you.

Open each level access landscape and import the heightmap.
or start from scratch using the tiles on import, which works much better.