There are many ways to create a hybrid conference, the following shows an example.
Before You Begin
Make sure you have connected a mobile phone to your phone.
Procedure
1.
Place a mobile call over Bluetooth on the mobile phone.
2.
Place a call on the phone.
3.
Tap Conference.
On the phone, select Invite.
4.
Tap the hold call.
The calls are merged into a conference call.