ROS2: list nested parameters that are undefined

General
1

So, what I was using in ROS1, were parameters like this to configure my controller:

        servos:
            leg_fr_alfa:
                id: 31
                joint_name: leg/fr/alfa
                from_servo: 772
                to_servo: 393
                from_angle: 0
                to_angle: 1.5708
            leg_fr_beta:
                id: 32
                joint_name: leg/fr/beta
                from_servo: 0
                to_servo: 1000
                from_angle: 0
                to_angle: 4.16784

How to properly handle this in ROS2?

I am not aware of a method to declare this parameter structure (or, more generaly, how to declare parameters which value is actualy complex structure).

Given that I allowed un-declared parameters and tried to use node->list_parameters({"servos"}, 2) to get the list of parent names for servomotors, but now I figured that list_parameters does not explire undeclared parameters.

So, what is the proper way to parse complex/nested parameter trees in ROS2?

2

These type of questions should not be asked here, but on https://answers.ros.org/

Anyhow, the first result on google for “ros2 nested parameters” is the following
https://answers.ros.org/question/325939/declare-nested-parameter/