Creating Network Between Macbooks for Screen Sharing I have 1 Macbook Air and 1 Macbook Pro.

Macbook Pro screen is broken so I log into Macbook Pro by Screen Sharing app on my home local network and view it in my Macbook Air.

But for traveling, e.g. Hotel, how can I create a network between Macbook Air and Macbook Pro so that they can find their IPs and connect through Screen Sharing app? 

Is it necessary to have router or modem to have those computers in network? Or is there any cable solution between computers that it can allow me to use Screen Sharing app?
You can create an ad-hoc (computer-to-computer) network which will allow the two computers to talk.  

Click on the Wifi icon in your menubar.
Click Create Network....
Put a Network Name (SSID) in the dialog box, choose a channel.
Click the Create button

On your other computer, join that network like any other Wi-Fi network.

You may be prohibited from creating an ad-hoc network. If so:

Go to System Preferences -&gt; Network -&gt; Wi-Fi. 
Click on the Advanced button, then the Wi-Fi menu item.
Deactivate the checkbox require admin to Create computer-to-computer networks.