Tested with cookiecutter version: 2.5.0 and main

Prior to Version 2.2.0 one could have a cookiecutter.json with a dict as value like so:

{
  "mainkey": {
    "subkey1": "value1"
    "subkey2": "value2"
   }
}

and then define an YAML to pass in with --config-file like so:

default_context:
    mainkey:
        subkey1: value1
        subkey2: value2
        subkey3: value3
        subkey4: value4

And after this, in the template with cookiecutter.mainkey one got all subkey1 to subkey4.

The feature #1692 here broke this (even if there were already some other fixes to this).

After 2.2.0 all we got are subkey1 and subkey2.