Not sure how you got into that state... but the XPath is invalid, which is why you are getting the error.
..[1]/my:GroupAction[1]/@my:Progress
You can't have the filter "[1]" on "..". These kind of filters only work on valid node names.
".." only goes up the tree [1] anyway... so a valid XPath, from what you've shown here, would be:
../my:GroupAction[1]/@my:Progress