Have you looked at the online help - Watermarks—Survey123 for ArcGIS | ArcGIS and it appears that you will need to have the set of questions that you want to reference as part of the watermark within your survey and then you would pull them for the mark.
It appears as though they have an example within Survey123 Connect that would help you in building what you need. This is from the help page. It appears as though you would Calculate a new question that contains what you would like to appear within the watermark and then call that question.
Within this geonet topic you will find an example of how to construct a question based on previous answers into one question that could be referenced within the watermark. https://community.esri.com/thread/194609-not-your-standard-note-question-email-link
Note:
If your combination of properties includes a space anywhere within it, enclose everything after the watermark parameter with double quotation marks.
Additionally, you can't reference the value from another field as a component of a greater watermark statement. Instead, you need to extract the desired value in another question, and construct the body of the watermark statement in the calculation column of the same question, including all variables. This value can then be referenced in the bind::esri:parameters column of the image question. Refer to the watermark sample survey available in Survey123 Connect for an example. Be aware that a calculated watermark statement like this doesn't need double quotation marks.
Cheers!
Mike