No, the organizations are a display thing only. They don't bring additional permissions.

Permissions to edit are per-collection.

How many "organizations" do you have?

Maybe you could have one "hidden" collection per "organization" with different permissions each, and then one public/visible collection that aggregates all the posts of the organization collections?

PS: if you can describe you use case in more detail, I would be very interested.

Ah, hm... That sounds like too much work because we are talking about actual organisations who will (hopefully) become members over time. So, I cannot even predict how many.

I could maybe just instruct users to change over the post owner to another user if they don't manage/want to complete the post themselves. That should work without special admin permissions, right?

I'll PM you with the background details. That doesn't need to be discussed here.

@bluesteens wrote earlier:

Ah, hm... That sounds like too much work because we are talking about actual organisations who will (hopefully) become members over time. So, I cannot even predict how many.

OK, assuming it will be more than a dozen organizations, my previous solution would not be very practical.

@bluesteens wrote earlier:

I could maybe just instruct users to change over the post owner to another user if they don't manage/want to complete the post themselves. That should work without special admin permissions, right?

Yes that will work.

The other solution would be to let them all log from the same - call it - a "common account".
I have been doing this with some of my users in the past.

Yeah, gerardp, it seems the most convenient way. Tbh, I think users will do this anyway, but I cannot suggest it officially. It increases the security risk when the login is shared. I have a paragraph in my T&C to put all the responsibility to the account holder. Nevertheless, it's not best practice to share login data.

I agree, it's not best practice.
I only do this for clients, and make sure their access is properly limited.