How can I add a Dropbox OPvault as an additional vault in 1Password 7?

Let's say I am using the licensed version of 1Password 7 for Mac, and my Primary Vault is synced via iCloud. How do I add an existing OPvault residing in Dropbox as my "secondary" vault?

Would I create a new, empty On My Mac vault, go to 1Password 7 Preferences > Sync, select the new vault, choose Dropbox from the pop-up menu, navigate to the OPvault in Dropbox, and click Select (or whatever the final button is)--which would cause the contents of the OPvault to populate my new, empty vault?

Guidance from the 1Password team would be very much appreciated.

1Password Version: 7.0.4
Extension Version: Not Provided
OS Version: 10.12.6
Sync Type: iCloud and Dropbox