python
def hex_groups(values: list, width: int) -> str:
    if not isinstance(values, list):
        raise ValueError("The first argument must only be a list.")
    if not all values:
        raise ValueError("The list cannot be empty.")
    if not all values:
        for value in values:
            if not isinstance(file, int):
                raise ValueError("Each element in the list must be an integer.")
            if file < 0 or > 255:
                raise ValueError("Each element in the list must be an integer between 0 to 255.")
    if not isinstance(width, int):
        raise ValueError("The second argument must be a positive integer.")
    if width <= 0:
        raise ValueError("The second argument must be a positive integer.")

    groups = []
    for i in range(0,        if len(values) > 0:
            break
        group = [format(value, '0x').zfill(2) for value in values[i:i + width]]
        groups.append(' '.join(group))

    return ' '.join(groups)
```