Hi David.
Thanks for help me.
I managed to make it work the way I wanted.
I understood better how to use leave_conference, so I was able to make it work the way I want.
In cionfbridge.conf I setting option 6 to be leave conference.
6=leave_conference
extensions.conf
[incoming-bridge]
exten => s,1,Answer()
exten => s,n,ConfBridge(1,1,default_user,sample_user_menu)
exten => s,n,Goto(other-bridge,s,1)
[other-bridge]
exten => s,1,Answer()
exten => s,n,Playback(beep)
exten => s,n,ConfBridge(5,5,default_user,sample_user_menu)