(B) Ownership of tiered entities For purposes of this section, if by reason of holding an interest in a trade or business, a decedent, any member of the decedent’s family, any qualified heir, or any member of any qualified heir’s family is treated as holding an interest in any other trade or business— (i) such ownership interest in the other trade or business shall be disregarded in determining if the ownership interest in the first trade or business is a qualified family-owned business interest, and (ii) this section shall be applied separately in determining if such interest in any other trade or business is a qualified family-owned business interest. (C) Individual ownership rules For purposes of this section, an interest owned, directly or indirectly, by or for an entity described in paragraph (1)(B) shall be considered as being owned proportionately by or for the entity’s shareholders, partners, or beneficiaries. A person shall be treated as a beneficiary of any trust only if such person has a present interest in such trust. (f) Tax treatment of failure To materially participate in business or dispositions of interests (1) In general There is imposed an additional estate tax if, within 10 years after the date of the decedent’s death and before the date of the qualified heir’s death— (A) the material participation requirements described in section 2032A(c)(6)(B) are not met with respect to the qualified family-owned business interest which was acquired (or passed) from the decedent, (B) the qualified heir disposes of any portion of a qualified family-owned business interest (other than by a disposition to a member of the qualified heir’s family or through a qualified conservation contribution under section 170(h)), (C) the qualified heir loses United States citizenship (within the meaning of section 877) or with respect to whom an event described in section 877(e)(1) occurs, and such heir does not comply with the requirements of subsection (g), or (D) the principal place of business of a trade or business of