You can't have multiple rules for the same traffic. There are iptables rules for the MITM transparent proxying of traffic. What you need to do is create a prerouting rule that will tee or copy the traffic..
iptables -t mangle -A PREROUTING -p tcp --dport 80 -j TEE --gateway BURP_IP:PORT
This is used to explicitly override the core network stack’s routing
decision. mangle table.
Route the packet through ‘ifname’ network interface
Change the packet’s incoming interface to ‘ifname’
Route the packet via this gateway
Behave like a non-terminating target and continue traversing the
rules. Not valid in combination with ‘--iif’ or ‘--tee’
--tee Make a copy of the packet, and route that copy to the given des-
tination. For the original, uncopied packet, behave like a non-
terminating target and continue traversing the rules. Not valid
in combination with ‘--iif’ or ‘--continue’