How do I create a random level from preset tiles?

I want to build an infinite level for a platformer by randomly combining hand-made 'sections'. What's the best way to achieve this? Very new to construct btw.

I started by manually creating my preset 'sections' as instances of a tilemap object, and picking them by instance variable, but I can't figure out how to programatically create/duplicate a specific instance. Also thinking ahead, these sections will need to be groups (mix of sprites, tilemap etc), rather than just tilemap instances.

Any help greatly appreciated :)

I just recently made this demo:

howtoconstructdemos.com/generate-random-levels-from-pre-built-scenes

I just recently made this demo:

https://howtoconstructdemos.com/generate-random-levels-from-pre-built-scenes/

Thanks so much, this looks perfect.