Managed to link two overworld portals together to one in the nether
I believe the two portals in the overworld have to be under 128 blocks apart total and also should be at least 8 blocks apart horizontally. I just used some simple 3D coodinate math and built the one in the nether at the midpoint....
![](https://kbin.cafe/media/cache/resolve/entry_thumb/bf/fc/bffc04ebebd5e664dae8070dcd778c1a3095fbafbc5980bac0989f6927ed2b6b.png)