ros2 launch: How to select parameters yaml file depending on parameter?

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I want to use a parameter (ns) to select the yaml file to load for parameters. I have a hard time finding how to do it... Is there a better way to do it?

I want to do something like:

def generate_launch_description():
    ns_arg = DeclareLaunchArgument("ns", default_value=TextSubstitution(text="/dji0"))
    location_arg = DeclareLaunchArgument("location", default_value=TextSubstitution(text="granso"))

    location_config = os.path.join(
        get_package_share_directory('lrs_wdb'),
        'config',
        f'location_{LaunchConfiguration('location')}.yaml'
    )

    return LaunchDescription([
        ns_arg,        
        Node(
            package='lrs_wdb',
            output='screen',
            emulate_tty=True,            
            namespace=LaunchConfiguration('ns'),
            executable='wdb',
            name='wdb',
            parameters=[location_config]
        )
    ])

But this is not working since "LaunchConfiguration('ns')" is an object. And googling it I did not find a strightforward way to get the value. So any suggestions how to solve this? I could use an environment variable I suppose but I do not think that is a good solution since for example ns is specified with a parameter.