Hi
Yes it is.
1) Log into your Joomla Dashboard
2) In the top menu, under Extensions click Template Manager
3) In the top right, click the Options button
4) Set Preview Module Positions to Enabled and then click Save & Close
5) Click the Templates tab
6) Next to the template you would like to view the structure of, click Preview
7) A new window will open and it will outline the structure of the template.
Cheers