Both @els and I have followed several courses there, so please don’t hesitate to ask us more about it.
Another one that I found very valuable, is on Spotify. It’s a set of 8 intermediate classes with Marshall Rosenberg, of which the first 7 deal with messages that are difficult to hear, or with people who are very upset. It’s maybe not directly applicable during facilitation, but I think it has some interesting learning points nevertheless.
Link to the first episode: Spotify(the sound gets better in the second episode)
Link to a long list of training courses with Marshall Rosenberg: Spotify