Existing 3-way Zwave dimmer setup - Need Help

I had an existing Zwave HA setup in my new home (using Clare Systems). I’ve replaced the hub with a Smartthings, and have almost everything setup. I’m having issues with a three-way dimmer. The living room has two Zwave dimmers that are supposed to control the light. One controls it directly, and the other is an “Auxilary” switch that seems to do nothing on it’s own. In the Clare system, it was designated as AUX. I’m trying to figure out how to pair it to the other switch in ST. I have both devices linked, and they show up as Z-Wave Dimmer Switch Generic. Of course the primary is working fine, but I don’t really know how to get the AUX to work, too.

I don’t know excatly what model dimmer you have, but in general any auxilliary dimmer/switch gets wired to the master and only the master does load control. Usually there are two wires between them (neutral and traveller).

I didn’t actually wire the switches myself. They were already installed, so I’m not sure how they are connected.