Client -> server -> multiple servers(peers)

Any sample sip.conf & extensions.conf for following scenario

Client (invites) Server1 (invites)
(Server2)
(Server3)
.
.
(ServerN)
Server1 is user and others are peers
Thanks in Advance

Only clients can invite in SIP. That is fundamental to the protocol.

What to you mean by “peers”?

There are examples of Asterisk setting up outbound calls (which can be a mix of technologies, including analogue) and discarding all those except the first to answer. These are in the sample extensions.conf.

If you mean a branched INVITE, that is something for which you would need a proxy. Asterisk doesn’t support that when acting as client.