If by User Title, you mean the text underneath my name, then this is how you do it.
Click '
Settings' in the top right corner of the page.
On the left hand side of the 'Settings' page, scroll down until you can see '
Edit Profile', click that.
On this page, the second box down says '
Custom User Title'. Type whatever you want to go underneath your name, in the little text box below.
Then scroll to the bottom and click '
Save Changes'
This should work.
If by User Title, you meant User Groups, then you can find out about them
here.