Links to view the layer on the NAvigator includes the domain twice. For example:

https://mitre-attack.github.io/attack-navigator/beta/enterprise/enterprise/#layerURL=

This is because the navigator instances in the config already specifies the domain URL, but the code still appends the domain suffix to the URL in the navigator macro:

https://github.com/mitre-attack/attack-website/blob/develop/attack-theme/templates/macros/navigator.html#L21

Removing the {{layer.domain}} suffix should fix the issue.

See also this commit for a manual patch fixing the built content: 36d72f6