Hi Jay,
Unfortunately, it is not currently possible to add text or distinguish particular repeats within the 'repeat bar' area when designing a survey.
While you can change the color of individual repeats, it will not be applied to the 'repeat bar' area. If you'd like to play around with this, please refer to the documentation here...Esri custom columns—Survey123 for ArcGIS | Documentation
As for applying text or modification to the repeat bar itself, we do have this internally listed as a potential enhancement to address in the future. Having said that, it would be great if you would be willing to raise this as an official Enhancement request with Esri Technical Support. This allows us to effectively track the number of Survey123 users who have the same desired request and incorporate that into our planning.
Thank you,
Brandon