I just wanted to follow up on this, because I found another way to handle this.
First, to address Brenden's suggestion: that won't work -- you can't use wildcard selectors in Scopes.
The other way I've found is to set the scope path ("This scope covers") to something broad enough to cover all possible cases (even just "/" works). Then be sure to select "Apply to the whole section". Finally, add a condition to check the NodeAliasPath however you'd like. For example, using a Regex, like this:
Matches(Document.NodeAliasPath, "/Department/[^/]+/Calendar")
I'm not sure if there will be any performance issues here. I doubt it, because I think this is only checked once when creating a new document.
The main downside is that there's no way to give a scope a title or description. So when you're looking at your list of scopes, it only shows the Starting path, which won't be very descriptive in this case.