How can I create a CloudFront origin using a S3 directory bucket (express one zone)?

I apologize, but there seems to be a misunderstanding in your question. Currently, CloudFront does not support using S3 directory buckets (S3 Express One Zone) as origins directly.

S3 directory buckets are a relatively new feature designed for performance-critical applications requiring single-digit millisecond latency within a specific Availability Zone. They use the S3 Express One Zone storage class, which is optimized for high availability within a single Availability Zone.

The fact that you don't see your directory buckets listed as an option in the Origin domain > Amazon S3 drop-down menu when creating a CloudFront distribution confirms that this feature is not currently supported.

As for whether this is on the roadmap, AWS does not typically disclose future plans for service integrations. However, given that S3 directory buckets are designed for specific use cases with very low latency requirements, it's unclear if they would be integrated with CloudFront in the same way as standard S3 buckets.

If you need to use CloudFront with your directory bucket content, you might consider setting up a custom origin instead. This would involve:

1. Configuring your directory bucket to be accessible via a custom endpoint.
2. Setting up the CloudFront distribution with a custom origin, using the endpoint of your directory bucket.
3. Implementing appropriate security measures to control access between CloudFront and your directory bucket.

Keep in mind that this approach may not provide the same level of integration or performance benefits as using standard S3 buckets with CloudFront. If your use case allows, you might want to consider using a standard S3 bucket as the origin for your CloudFront distribution to take full advantage of the native integration between these services.
Sources
Creating directory buckets in an Availability Zone - Amazon Simple Storage Service
Cloudfront with other provider S3 | AWS re:Post