When you first upload, you must select "Private" and attach your video. Then while the video is being uploaded, near the privacy setting for that video, there is a button called "Share".  Under that is a tickbox that says "Let everyone at mindmotionacademy.com view". You can tick that box to enable to share with Mind Motion Academy..

If you miss this opportunity, there is no option to do it later. If you accidentally load the video as Public and then take it back to Private, there is no opportunity to do this process.  Instead, your video must be deleted permanently from YouTube and then re-uploaded to give yourself this option.