def convert_value_to_string(dictionary):
    """Convert all nested lists of a single value to an item

    Parameters
    ----------
    dictionary: dict
        nested dictionary with nested lists
    """
    for key, value in dictionary.items():
        if isinstance(value, dict):
            convert_value_to_string(value)
        else:
            dictionary.update({key: str(value)})
    return dictionary