Self intersecting curve to surface

Hello everyone, I got this self intersecting curve which I’m trying to convert to a surface while dismissing the external edges. I tried the shatter command but it could only delete one of the 2 extra edges… after trying the operation again o the remainder, it remains the same.
Attaching a picture.

I guess you might use self intersection and / or discontinuity, but it’s pretty difficult to say without your GH file with internalized geometries