You can use a "tracking stock" approach. Under this approach, the Qualified Opportunity Fund (QOF) would be formed as an LLC, each of the QOF's projects would be held in a separate LLC and the QOF would hold 99% of the membership interests of each project LLC (so that each project LLC is treated as a partnership for tax purposes). The operating agreement of the QOF would have a separate distribution "waterfall" for each of its project LLCs. An investor's capital contribution to the QOF would be pushed down only to the project LLC in which he wants to invest, and he would participate only in the waterfall for that project LLC.