Hello there, Nubiru.
The following Knowledge Base article reviews the process for Hiding purchases:
iTunes Store: Hiding and unhiding purchases
http://support.apple.com/kb/ht4919
Specifically the following:
To hide your purchases
- Open iTunes on your computer. You can download the latest version of iTunes here.
- From the Store menu, choose Store > Sign In, and then enter your Apple ID and password.
- From the top navigation bar in the iTunes Store, click on a desired content type (Music, Movies, TV Shows, App Store, or Books).
- Click Purchased from the QUICK LINKS section located on the right of the iTunes Store.
- Choose a content type by clicking on Music, TV Shows, Apps, or Books from top.
- Hover your cursor over the item you want to hide.
- You will see an "X" either to the right or left top corner of the item.
- Click the "X" to hide that item. A confirmation dialog will appear once you click the "X."
Thanks for reaching out to Apple Support Communities.
Cheers,
Pedro D.