Hi.

I have successfully joined the ZeroTier network with my RB4011iGS+5HacQ2HnD router and added a firewall rule to accept all connections from the ZeroTier interface.
How would I go about setting the routes, so that any device in my ZeroTier network could communicate with any device in my Mikrotik network and vice versa? I'd appreciate a step by step guide if possible.

Adding routes for mikrotik is covered in the help doc's, but I don't think that's what you actually want since the tik already knows about the network. You want to add a route in your zerotier network that points to your tik. If you can't figure out how to do that you may want to ask a zerotier forum.

Just had to add a route in my ZeroTier configuration, the upper being my home network and the lower being my ZeroTier network. I'm using /26 subnet mask, because the free ZeroTier is limited to 50 clients anyway.