wpbakery get parent container element's paremeter value inside child contentainer in visual composer

Question

I have created some Visual Composer Elements with parent and child attributes using "as_parent" and "as_child" parameters. I have added some fields in parent container and some fields in the child container. What I need is to populate a child element's parameter value according to the value in the parent element field. Is there any method I could follow to accomplish it.

Here is some of the portion of my code vc_map( array(

    "name" => __("Image Gallery", "textdomain"),
    "base" => "test_image_gallery",
    "as_parent" => array('only' => 'test_gal_single_element, test_gal_cat_element'),
    "content_element" => true,
    "show_settings_on_create" => false,
    "is_container" => true,
    "params" => array(

        array(
            "type" => "textfield",
            "heading" => __("Add Filters", "textdomain"),
            "description" => __( "Enter filters separated by commas. eg: filter1, filter2 etc", "textdomain" ),
            "param_name" => "add_custom_filters",
            'dependency' => array(
                'element' => 'show_filter',
                'value' => 'true',
            ),
        ),

    ),
    "js_view" => 'VcColumnView'
    ) );


vc_map( array(
    "name" => __("Idea", "textdomain"),
    "base" => "test_gal_single_element",
    "content_element" => true,
    "as_child" => array('only' => 'test_image_gallery'),
    "params" => array(
array(
            "type" => "checkbox",
            "heading" => __("Assign Filter", "textdomain"),
            "param_name" => "assign_filter",
            "value"       => array(
                'Wool'   => 'Wool',
                'Synthetic'   => 'Synthetic',
              ),
            ),
)
)

) );

So what I need is to have the values entered in the parent param "add_custom_filters" for populating the "assign_filter" inside the child container.

Thanks.