macOS Sierra: Create a computer-to-computer network
If you want to set up a temporary Wi-Fi connection between your Mac and another device, you can create your own network using the Wi-Fi menu.
Click the Wi-Fi status icon in the menu bar and choose Create Network.
Enter a name and choose a channel for your network.
When you create a computer-to-computer network, the Wi-Fi menu icon changes to show a computer . When you’re done, click the Wi-Fi menu again and choose Disconnect to close the network you created.