Probably via a Zanzibar-based system, excerpt from the Zanzibar paper [1]:
> [...] useful common infrastructure can be built on top of a unified access control system, in particular, a search index that respects access control and works across applications.
> [...] useful common infrastructure can be built on top of a unified access control system, in particular, a search index that respects access control and works across applications.
[1] https://authzed.com/zanzibar/28Sa8hWHLG:e:1I