Hi, Brooke:
Is your button in the repeating group? Or do you have one button that is supposed to calculate all the repeating groups?
If the button is inside the repeating group, you can use the eventObj variable to select the correct instance of the group.
Your button's event handler looks something like this (with the CTRL name depending upon the name of your control): Sub CTRL1_5_OnClick(eventObj)
If you use eventObj.Source.selectSingleNode("xpath") you can get the fields in the group the button is located in. For example, say the xpath to my field is this: /my:myFields/my:topGroup/my:repeatingGroup/my:rgField1 and my button is sitting in my:repeatingGroup. To get my:rgField1, I could use eventObj.Source.selectSingleNode("my:rgField1").
Now, if you have one button on the whole form, and you want to run calculations for all the groups, instead of using selectSingleNode, you'll use selectNodes and iterate through all the nodes, performing your calculations on each group as you go through. Does that make sense? Let me know if you need more help....