Install local package with local dependency

Hey,
I want to install a local package which depends on an other local package:

nix-env -f /home/onny/projects/nur-packages -iA fragments

But the local dependency libtransmission couldn’t be found :frowning: It is in the same package directory https://git.project-insanity.org/onny/nur-packages/-/blob/master/pkgs/libtransmission/default.nix

What is the best way to reference it?

Best regards
Jonas