Playing fullscreen in the same window I have Vlc version 2.1.4 operating on Mac OSx Yosemite.  When I open any VLC video to fullscreen, it opens into a separate window, or desktop. What i want to do is to be able to fullscreen the video yet have it stay within the desktop that I used to open the file. Is that possible?
No. Since I think Mavericks, full-screen sets itself up as a new Space. You might be able to work around it on 2 monitors by using 'Displays have separate Spaces' in System Prefs > Mission Control.