With regard specifically to a virtual three-way, that’s a very common way to do three way switches in SmartThings. In fact, there are some Devices specifically designed for this.
One of the most popular is from linear/go control. Both the auxiliary switch and the master switch are Z wave devices. Both are mains-powered, and both require a neutral wire. But the auxiliary doesn’t attach to the load at all. So it can be placed anywhere you want. One of the Reasons for the popularity is that the auxiliary is less expensive than a typical load control switch.
Master:
https://www.amazon.com/Linear-WD500Z-1-Z-Wave-500-Watt-Wall-Mount/dp/B00E1OVFAK/
Auxiliary
https://www.amazon.com/Linear-Z-Wave-3-Way-Accessory-Switch/dp/B00EAY3K5Y/
As far as the name of what you’re looking for, it’s just an auxiliary switch for a virtual three-way. 
As @Jason_Brown mentioned, you can do this with many different switches. In a smartthings set up, you can have any switch follow another switch for basic on/off. The trick is to get dimming to work properly. For that you either need to associate the switches as in the FAQ for the go control devices, or you need to use a special smart app like Dim and Dimmer.
The main thing to know is that any auxiliary which communicates to its master through physical traveler wire can’t be used in a virtual three-way. But as long as the auxiliary is recognized by smart things as an independent dimmer, you can probably set it up.
( I feel like I’m not being very clear today, so I hope that wasn’t confusing.)