You want to create segments on UserGuiding using your data on Google Tag Manager data layer. Here is how to do it?
First, go to custom attribute create page.
Identifier is the field (key) in your event layer and also the custom attribute name.
Enter the data format that you store the attribute on data layer.
Select Google Tag Manager as Data Source
*Enter the event name of the data layer where you store the attribute.
*See example below
Let's say you've pushed following event to dataLayer, and you want to segment user based on their color choices.
Your configurations should be as follow;
Identifier --> color
Data Format --> Text
GTM Event --> customizeCar
So, our JS code will search for the event customizeCar on dataLayer. And use it's color value as custom attribute.
After you create the custom attribute, it's time to assign custom attribute to a segment.