@lungben, thank you. This is really close to what I need. I need to specify a path relative to the current working directory. Unfortunately, my attempts to modify your code did not work. Here is what I did:
path = pwd()
md"""
[my_link](./open?path=$(path)/my_notebook.jl)
"""
Error:
Please check whether /home/dfish/.julia/pluto_notebooks/$(path)/my_notebook.jl exists.
Is there a way to interpolate the path variable? I thought that $() would work.