This is very difficult to answer due to that very often Teamcenter installations are customized such that searching for example looks / works differently.
In our install, I would initiate a "general search" and then we have a pulldown dialog where I can select the user.
There is also in NX an advanced search in the Teamcenter navigator-tab. This works slightly different from the Teamcenter search but you can also set the user as a search criteria there.
Regards,
Tomas