How do I fix this simple intersecting geometry? I have this shape here I made from curves:


It works fine in renders and viewport but I want to use it as object for boolean but it's not working because it has intersecting geometry:


How do I fix the intersecting geometry to make it usable for boolean?
You could:


Delete 'Faces only' the curve-shape, leaving a network of edges
Knife Project the network down onto a plane





Delete away unwanted parts of the plane
X > Limited Dissolve unwanted edges (there may be some minor repair work to do)
Extrude the result, which is then OK for a Boolean.