The connectors in a Reference Model define what connectors can exist in your model. For example
If your Reference Model has a connector as shown above, then A’s can have dependency connectors to B, bit not the other way around.
If you create a b-directional link in your Reference Model, then this means the model can also have b-directional links. Bi-directional links are quite unusual. What’s more common is to allow connectors to point in both directions.
If you need links from A’s to B’s AND from B’s back to A’s, then your Reference Model must look like this: