Potentially there could be both. And if people enter themselves in the master directory, they could get a pop up informing them of their local group’s directory or way of networking, and could be asked if they’re happy for their info to be automatically added there as well. And vice versa if they add their info to the local group’s directory (or equivalent), as long as the local group’s approach involves people adding their info in some way.
That way both the centralised and local versions could grow together, but people would still have the choice to just be involved in one or the other if they prefer.
Just a thought—not sure how easy/useful it’d be to actually institute.
Personally, I think I’d benefit from and appreciate something like that system, if someone else put in the work to make it happen :D