How to configure a pull request quorum making an organizational constraint? Consider the following situation.

Alice and Anna, Bob and Bart, and finally Eve and Evelyn work on same Git project in three different organizations.

How can they configure a quorum for pull requests, which requires at least 2 votes but from two different organizations? 

Example:


Votes from Alice and Anna - no quorum achieved possible as both votes come from the same organization;
Votes from Alice and Bob - quorum has been achieved because team members from two different organizations have voted.
Although I like the idea, based on what I know while working with Gitlab, Bitbucket and Github I do not believe that it is currently possible as I cannot remember that such integrations were available.

Also Googling: github bitbucket pull request approvals integrated did not return any positive results.

I think that the users should always be part of the same organization in order to approve Pull Requests. However, when I think about github I can remember that I was able to invite people as a collaborator even when they were not part or part of any organization.

In conclusion, I think that it is possible, but only in a certain git-server providers like GitHub. My suggestion is to try it and otherwise report an issue in the associate Github project.