Unable to capture node-to-node traffic in a wireless access point

I have created a wireless access point on ubuntu and I have written a program that parses network traffic obtained via tshark and condenses it into a readable form. I am able to capture traffic going to and from the internet. Now i have three nodes on my network: **Node A**: The wireless access point running tshark **Node B**: Computer 1 **Node C**: Computer 2 To create TCP traffic in my network, i used nmap on Node A to scan Node B but i am unable to capture that traffic. Any clue how to do that? I tried putting my network interface card in promiscuous mode but that didn't help.