def unique_in_list(array, ignored_elements=()):
    """Returns unique elements in ``array``, removing
    all levels of nesting if found.

    Parameters
    ----------
    array : `list` [`any`] or None
        List of items, with arbitrary level of nesting.
    ignored_elements : `tuple`, default ()
        Elements not to include in the output

    Returns
    -------
    unique_elements : `list`
        Unique elements in array, ignoring up to
        `level` levels of nesting.
        Elements that are `None` are removed from the output.
    """
    unique_elements = set()
    if array is not None:
        for item in array:
            if isinstance(item, (list, tuple)):
                unique_in_item = unique_in_list(item, ignored_elements=ignored_elements)
                unique_in_item = set(unique_in_item) if unique_in_item is not None else {}
                unique_elements.update(unique_in_item)
            elif item not in ignored_elements:
                unique_elements.add(item)
    return list(unique_elements) if unique_elements else None