How do I make a rule apply only to campaigns with a certain name?

Use the Filter by name field when you create or edit the rule. The options are: Any (no filter), Contains, Does not contain and Starts with, followed by the text you want. The filter ignores uppercase, lowercase and accents: typing sabado matches campaigns with Sábado or SABADO in the name, for example. It applies to the scope you chose: if the rule is for Active Ad Sets, the filter compares against ad set names. This is the recommended way to isolate a campaign or group of campaigns without creating a separate account.