New Venture Fund is a nonprofit managed by left-leaning philanthropic consulting firm Arabella Advisors. Critics characterize New Venture Fund as a “dark money” conduit through which left-wing donors can donate money without having to disclose their identity or where the money is going. 
Social and Economic Justice Leaders Planning Group
Social and Economic Justice Leaders Planning Group is a coalition of unidentified left-wing groups that trains activists and employees in leadership and other activist activities. 
The issue focuses of the group is education, human rights and civil liberties, policy, and research and social science. 
A contact e-mail for a job posting associated with SEJLPG leads to the web domain sejleaders.org, but as of mid-June 2020 there is no publicly visible website at that address.