What you ask is impossible, if you have a foreground there also must be an background. If you want a foreground and a background in one layer, you neither have a foreground or a background as you need more than 1 layers to have both... otherwise the foreground will be the background and will therefore be neither one...
So if you give us some more info, what are you trying on doing? If you are following a tutorial, post a link so we can see. Maybe it is a good thing to post an screenshot of what you are trying to do/ are doing...
But as for bringing old... very old topics back to life, why silver bullet? why?
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