A survey was created in Survey 123, it has the layer with its data table, and a joined table. I want to use an attribute field from the layer, and see what entries come up in an attribute field from the related table, visualized within a chart widget. This is the most specific use case, though we have other related layers and tables, that have IDs to connect them, but aren't as formally joined as this, that we would love to build charts off of. I am open to using other apps, I have mostly looked at Dashboards as a secondary option.
A table join is very different to a related table. The terms are not interchangeable. I'm assuming you're not using joins and are talking about the survey parent layer + repeat (related table).
I would recommend Dashboards for this. Add your chart
https://doc.arcgis.com/en/dashboards/latest/get-started/serial-chart.htm
Then add a category selector and configure the actions to filter the parent and chart.
https://doc.arcgis.com/en/dashboards/latest/create-and-share/selectors.htm
Thank you very much!