how do i get my movies to show up in iTunes via the cloud on my mac air

Hello there, Jiker.

It sounds like you're not seeing your purchased iCloud movies in iTunes on your Mac. The following Knowledge Base article offers up steps on how to unhide them:

Hide and unhide purchases in iTunes or iBooks on your Mac or PC - Apple Support

Unhide your purchases

You can unhide music, movies, TV shows, or apps in iTunes and books in iBooks on your Mac or PC.

In iTunes

Click to open iTunes and sign in to your Account Information, or use the steps below:

1. Open iTunes.
2. Click Sign In, and then enter your Apple ID and password.
   
3. Click your name and select Account Info from the menu.
   
4. Enter your password again.

On the Account Information page:

1. Scroll down to the iTunes in the Cloud section. To the right of Hidden Purchases, click Manage.
   
2. From the upper-right hand corner of the Hidden Purchases window, click on a content type (Music, Movies, TV Shows, or Apps).
3. Below the item you want to unhide, click Unhide.
   

After the item unhides, if isn't already downloaded to your Mac or PC, it downloads automatically.

Thanks for reaching out to Apple Support Communities.

Cheers.