I see a lot of groups for managers/directors/VPs/CTOs/founders, but I can't recall ever seeing something for growth along the IC track.
Eventually you hit a wall with how far you can self-learn or through the people in your organization, so the only way to continue growing in any field is to find or build a support network around you of peers.
If it doesn't exist, I'll gladly make a Slack group.
Context: I've been a Principal Software Engineer for almost four years, in a team of 20-500 engineers. At our peak there was ~15/20 Staff/Principal/Fellow Engineers, and I learned so much from working with them and would love to continue learning from my peers.