Thank you so much for your reply! I appreciate your help!
From the above link and Greg's blog, I now have a field "Current Position" whose default value is count(preceding-sibling::ActionItems) + 1 to determine the number of nodes in the repeating section "ActionItems".
I am having difficulty, however, filtering by that number to reach the current node. I cannot seem to reference it correctly in my Xpath. My code now looks like this:
titlevar = XDocument.DOM.selectSingleNode("/my:Effort/my:Action/my:ActionItemsOpt/my:ActionItems[number(../my:CurrentPosition)]/my:ActionTitle").text
descripvar = XDocument.DOM.selectSingleNode("/my:Effort/my:Action/my:ActionItemsOpt/my:ActionItems[number(../my:CurrentPosition)]/my:ActionDescription").text
duedatevar = XDocument.DOM.selectSingleNode("/my:Effort/my:Action/my:ActionItemsOpt/my:ActionItems[number(../my:CurrentPosition)]/my:ActionDueDate").text
...
I would really appreciate any help you have!