Yes and no. At least for Creo View Lite.
In the past you would be able to select one thumbnail to open in Creo View then find another and do the same thing. After selecting the second thumbnail it would ask if you want to "Add to Current Session" or "Create a New Session". If you select the Add to option it would create a second window in the existing Creo View.
Now what happens, and I don't know when this started, is the first time you select a second thumbnail it would give you the "Leave this page" or "Stay on this page". So it will remove the first one added. If I go back to the to the first one and click the thumbnail then it will give me the "Add to Current Session" or "Create a New Session". But that still doesn't work very well.
I submitted a call and they said it is a known issue with Internet Explorer. If you try that with Chrome it will open separate sessions of Creo View. Many people at our company don't have Chrome and our IT manager doesn't want to support it. We have another company-wide program where parts do not work in IE so they had to install it for those users.
VERY DISSAPPOINTING!
There is a document on PTC's site about it.
Document - CS37699