How to record when the "previous" button is used?

Using a comment from TomG on this post, I have come up with the following code, where I initially create an empty embedded data "backbutton" in the survey flow:
  var qid = this.questionId;
  var back = Qualtrics.SurveyEngine.getEmbeddedData("backbutton");
  jQuery("#PreviousButton").click(function() { 
      if (back == null) {
         back = qid + "-";
      } else {
         back = back + qid + "-";
      };
However, I have looked for a way to append the question custom label/tag (i.e. "DataExportTag") instead of the question ID in vain. Does someone know of a way to do so?

I believe the only way to get the question label is to turn on Question Numbers under Survey Options. Then it is a label with the class ExportTag. You'll have to have your JS hide it if you don't want the respondent to see it.

You can fetch the export tag using the below,
var currQn =  jQuery('.ExportTag').html().slice(0,-1);
store the currQn in embedded data variable.
This is to work in live mode, you will have to enable the question numbers in live and you have to hide the question numbers using the CSS.