An appeal will be limited to those issues that were before the administrative law judge or Indian probate judge upon the petition for rehearing or reopening, or regarding added or omitted property or purchase of interests in an estate, or before the BIA official on review. However, except as specifically limited in this part or in title 25 of the Code of Federal Regulations, the Board will not be limited in its scope of review and may exercise the inherent authority of the Secretary to correct a manifest injustice or error where appropriate.