I'm not entirely sure what you're describing. A screenshot would be nice, photoshopped if necessary.
I suspect this might be involved anyway, so I'll drop it here:
Warning: This plugin is not official part of OBS, the part "obs-" in the repository name is only to keep the repositories organized, not to identify this plugin as part of OBS. The name of the plugin, the module name and project name all don't...
obsproject.com
It basically creates another layer of scene switching, independent of OBS's normal one, and puts the output of that over the top of OBS's main output. So your tickers and things can be in there, and your cameras in the main set, or whatever.
Just make sure that your overlay scenes are not 100% opaque! 'Cause they're fullscreen too, and will completely cover the main out if they have non-transparent content everywhere.