You can move your rules to another phone, keep a copy, or share them with someone you're helping.
Export: in Settings → Rules, open More options → Export rules… and choose where to save the file.
Import: on the other phone, More options → Import rules… and pick the file. You see "Imported … rules"
Rules files contain only the rules, no messages or numbers from your conversations (except numbers you typed into a rule yourself). Import only files you trust: a rule can, for example, trust a sender.
To move everything (messages, senders, history and rules), use Export everything instead.