You could create 3 vaults: 1 vault that's a container, and then have the 2 other vaults as it's dependencies. If you don't want to keep any notes in that container vault, you could delete the

notes

folder and remove it as an option from the config (it will be listed as

fsPath: .

in the

dendron.yml

). That's identical to what workspaces are in Dendron right now though, so you might as well just create a workspace as usual.