How to fetch data of a blank subform

Good Morning,

I have a form with deluge name Sales_Manual which consists of a decision box (Name 'Upload') and a blank subform (Name 'Spa_Table').
Blank Subform has two single line fields 'Location' and "Main_Building_Level_3"

I would like when I click the decision box then to load in the blank subform the values of a specific (already) inserted record.

I am doing something wrong in my code (inside the loop) because the below returns the same value in each record of the subform

if (Upload)
{
   for each rec in Sales_Manual [ID = 1721972000087607052]
    {
         for each subrow in Spa_Table
         {
              for each rec1 in rec.Spa_Table
        {
                   subrow.Location = rec1.Location;
                   subrow.Main_Building_Level_3 = rec1.Main_Building_Level_3;
           }
         }
    }

}

If you need more info I can send you.