For the field object I am getting below array that doesn't have the group name.

CRM_Core_DAO_CustomField Object
(
    [id] => 61
    [custom_group_id] => 12
    [name] => checkbox
    [label] => Text
    [data_type] => String
    [html_type] => Text
    [default_value] => 
    [is_required] => 0
    [is_searchable] => 0
    [is_search_range] => 0
    [weight] => 1
    [help_pre] => 
    [help_post] => 
    [mask] => 
    [attributes] => 
    [javascript] => 
    [is_active] => 1
    [is_view] => 0
    [options_per_line] => 
    [text_length] => 255
    [start_date_years] => 
    [end_date_years] => 
    [date_format] => 
    [time_format] => 
    [note_columns] => 60
    [note_rows] => 4
    [column_name] => checkbox_61
    [option_group_id] => 
    [filter] => 
    [_DB_DataObject_version] => 1.8.12
    [__table] => civicrm_custom_field
    [N] => 1
    [_database_dsn] => 
    [_database_dsn_md5] => d4ac5b06b5b579be21cd6aa8f8a93251
    [_database] => civi
    [_query] => Array
        (
            [condition] => 
            [group_by] => 
            [order_by] => 
            [having] => 
            [limit_start] => 
            [limit_count] => 
            [data_select] => *
        )

    [_DB_resultid] => 33
    [_resultFields] => 
    [_link_loaded] => 
    [_join] => 
    [_lastError] => 
)
Am I missing something here?