As an example from the recent past, this was covered in a change to PSF’s by-laws in https://github.com/psf/bylaws/commit/c00cc2157d843ed0302971cf7e1eecc8edfd521d
For purposes of this Section, a common affiliation includes all
organizations that, directly or indirectly through one or more
intermediaries, controls, is controlled by, or is under common control
with the other entities declared as affiliations by other members
of the Board of Directors.