Relative import beyond top-level package

Question

After many searches and attempts I have not found a solution to this problem...

I am using Sphinx to generate documentation for a Python package. You can see the code here: https://github.com/jajimer/energym/tree/documentation. The part of the package we are interested in is organized as follows:

In energym/docs/source/conf.py I have configured the path as follows:

import os
import sys

sys.path.insert(0, os.path.abspath('../../energym/'))

And now I'm trying to add to the API documentation (energym/doc/source/pages/API-reference.rst) the description of this utils module and all its components. For this, I am using Sphinx's autosummary:

.. autosummary::
   :toctree: modules
   :template: custom-module-template.rst
   :recursive:
   
   utils

So, after doing make clean && make html, the documentation for utils.common, utils.rewards and utils.rewards is perfectly created, but not for utils.controllers. According to Sphinx, the following exception occurs:

File "/home/user/projects/energym/energym/utils/controllers.py", line 8, in <module>
    from ..utils.common import parse_variables
ValueError: attempted relative import beyond top-level package

And here is my question. How can I fix it? Is it a relative path problem? I've seen that the problem is due to the following import:

from ..utils.common import parse_variables

But I don't really know the reason, as the path seems to be perfectly set.