I had my question answered in the following StackOverflow topic here
Jimmy, your expression was able to bring another StackOverflow member to the answer that worked for me. Due to my limited understanding it may be that I was unable to recognize how Jimmy's original statement could have worked in another, similar situation. Either way I hope this helps others as well!
contains(//my:RepeaterSection[0=count(following-sibling::my:RepeaterSection)]//my:TargetNodeName,'TargetString')