How to edit .imovielibrary extension as project?

On iMovie 10.1.6 for Macbook Pro High Sierra 10.13.6— I’m trying to edit a project/clip which has been autosaved by iMovie with a .imovielibrary extension.

When I try to open it to edit in iMovie, it shows me the saved movie clip in My Media and allows me to drag to panel below. Doing so seems to have saved none of the transitions, overlaid music, etc necessary to make additional edits. Checking My Movie above in Project Media is the same story.

Question: How can I recover / open the video clip with the transitions, overlays, etc so I can begin where I left off?

enter image description here

Then I thought I should click on All Events then drag them onto the library clip but it won’t let me drag or otherwise add the events:

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Originally I thought I may have lost them, so I checked in the cached folder and it’s the same deal here (no editable “project” files):

~/Users/me/Library/Containers/com.apple.iMovieApp/Data/Library/Caches/iMovie Backups.localized