In computing the holdings of a private foundation, or a disqualified person (as defined in section
4946) with respect thereto, in any business enterprise, any stock or other interest owned, directly or indirectly, by or for a corporation, partnership, estate, or trust shall be considered as being owned proportionately by or for its shareholders, partners, or beneficiaries. The preceding sentence shall not apply with respect to an income or remainder interest of a private foundation in a trust described in section
4947
(a)(2), but only if, in the case of property transferred in trust after May 26, 1969, such foundation holds only an income interest or only a remainder interest in such trust.