As there are so many variables I can never give folk a step by step. But do check out the basics.

First, no, it does not mean these are on different networks. Each PC can call the connections and network a different name. Confusing but something i ignore.

Here's my work list.

1. The printer must be shared. (articles on the web so I don't copy that here.)
2. You have the right network. Read
3. Routers today offer firewalls. These can block printer and other network shares and I'll debate if they offer any real protection that we didn't have before. It's highly technical so I can't write at length but if items 1 and 2 are right, I turn off the firewall in the router.