A team-call group in Skype for Business is a group of people who can answer your phone calls when you are not available. You can add and remove people to the group, and other people can add you to their team-call group.
Setting up your team-group
1. From Skype for Business, click the settings cog, and call forwarding settings
2. Select Edit my team-call group members
3. You can then manage your group by adding (or removing) members
4. Once the group has been set up, you need to tell Skype for Business to ring members of the group when you get a call. Go back to the call forwarding settings (Skype for Business > settings cog > call forwarding) and select simultaneously ring
Managing your team-call group
When your team-call has been set up, there are various options you can choose from.
For example, you can choose a different ring tone for the team-call or turn the ring tone off for your team-call (so the members of your group receive a call alert rather than multiple phones ringing). These options are found under Skype for Business > settings cog > ringtones and sound
More information about call forwarding in Skype for Business from Microsoft.