With Search forms and potentially and Chorus form designed for work processing whether UXBuilder, Dynamic Forms, or Traditional forms the ability to denote a one of these are required. My thought on implementation would be to contain the fields within a group box and mark the box with a css class of oneOfThese. There could be multiple group boxes with independent oneOfThese markers. This was implemented as custom javascript on a Search form that required a hidden text input that was marked required that the custom javascript managed inputting/clearing to get the Search button enabled/disabled appropriately.
