Can you expand a little more in what format you would like the data exported? If you export the data in an Excel spreadsheet each related table will get it's own worksheet. Survey123 uses GlobalID to ParentGlobalID relationships to relate records from a related table to the parent table. In the exported Excel spreadsheet you will have the Global ID in the parent table as well as the ParentGlobalID in the related table which will match. If you would like to merge the tables you can use the GlobalID/ParentGlobalID columns in both tables to merge them together.
Thank you for your response! I am looking to export in an Excel spreadsheet. I had found the GlobalID/ParentGlobalID relationship but didn't think about merging the worksheets using a formula. That's exactly the answer I was hoping for. Thank you for your help!