Grouping lights, controlling multiple switches with one Tile

Updated February 2021.

1. Create a Simulated Switch, it will the the master switch for the group. Alternatively, if you don't want to create a virtual switch, you may chose to designate one of the devices in the group as the master switch.
2. In SmartThings mobile app open left hamburger menu, select SmartApps, select Smart Lighting, Create a new Lighting Automation
3. Select all lights that you want to control as a group under "Which devices do you want to control?"
4. Select "Mirror Behaviour" under "What do you want to do?"
5. Select the master switch from the first step under "Mirror which switch"
   

Now, the master switch can be added as a Tile!