If the person you are speaking to wants to talk to another colleague of yours, you can transfer the call that colleague. 

Confirm. 

Enter the number of the party to which you want to transfer the call. 

Announce the call, if necessary. 

Replace the handset. 

Select and confirm. 

...After a Speaker Call (Announcement) in a Group

If this function has been configured (contact System Support), you can use a speaker call (announcement, ) to announce a call in progress to a group of users .
After a member of the group has accepted the call request, you can transfer the waiting party. 

Precondition: You are conducting a call. 

Confirm. The other party is placed on hold. 

Press the key. The LED lights up. 

Select and confirm. 

Enter the code. 

Enter the group's station number.  

Announce the call.
When a member of the group accepts the call , you are connected to this party. 

Replace the handset. 

Select and confirm. 

If the connection between the two other parties is not established within 45 seconds, the call from the first part returns to you (recall).