Repeater XML is, if the Repeating Section is associated to a column (typically multi-line plain text), stored directly in the column - which is what you will use to reference anytime you need to get or set said XML. 

Repeater XML is, if the Repeating Section is not associated to a column, stored as part of the Form Data (referenced from the Common tab I believe) as Encoded XML which will need to be decoded before being useful. 

To test this, simply send yourself either the reference to the Repeating Section's associated column, or the Form Data in an email using Send Notification workflow Action. It should be noted however that you'll want to turn the Text Body to Plain Text as leaving it on the default Rich Text will result in bad data. 

After reading a few other threads, you can easily learn how to set your XML data to a column by following the instructions here: Repeated Section to Plain Text 

Also, as noted in the comments here:  using the Form Data may result in inconsistent behavior (in terms of encoded xml / decoded xml) which can lead to frustration, making the Column Association option all the more appealing. 

I hope that this gets you on your way. 

Thanks for the help ‌! I was already grabbing the XML and populating a separate column so once I just used that instead of referencing form data I got it working.

YAY!

Kassie

Excellent! 

Dealing with Repeating Sections is a bit of confusing thing at first, but it gets easier over time. 

If you don't mind, could you mark the answer as correct if you feel that it solved your problem? In the event that someone else has a similar question it could help act as a filter when they are searching the forums for answers  

Thank You, and I'm glad that it worked!