On the V2(earlier version) of Chargebee’s Customer Portal, you can group plans based on their billing interval.
To enable this option, navigate to Settings > Configure Chargebee > Checkout & Self-Service Portal > Customer Portal, here enable the “Change Subscription” option under “Allowed Actions” and select the ”View plans based on billing interval”.
Here’s a screenshot for your reference:
For the portal V3, we provide advanced customization options through the Custom Codes feature that allow you to group, hide or display different plans based on your business use case. You can also configure when the "Change Subscription" operation occurs based on the plans the customers choose. This feature needs to be enabled from the back end for your site and would require some development effort on your end. Please contact firstname.lastname@example.org to enable this for your site.
Here's the doc which has the instructions for configuring the grouping of plans in the portal.
Documentation link to get the change subscriptions options like end-of-term when a customer is changing his subscription. from the portal
Once this feature is enabled for your site, you can go to the link https://site-name.chargebee.com.custom_codes(replace ‘site-name’ with your Chargebee domain name) and upload your code. Here’s a sample JS code for your reference.