I have a select multiple question for users to select the lakes they use. Later in the survey, I have a select one question asking about which of those lakes pertains to a specific activity - is there any way to use the previous choice list responses as the pared-down version of the select one options?
You can use a cascading select to filter elements from a list in a select_one, but I do not think it quite fits what you are looking for. Cascading and external selects—Survey123 for ArcGIS | Documentation I believe there is not a practical way to do what you want.