Solution
Business entities may not show up if in case the entities were created in Chargebee post installing the Salesforce app.
In that case, you would need to go to add/remove domain and configure entities in Salesforce
You shall find that in Chargebee Settings > Advanced Actions > Add/Remove Domain
Related Articles and Documentation
https://www.chargebee.com/docs/2.0/salesforce-integration-guide.html