Are you using a plugin for your parallax, or the default facility? I sounds more like an overlay than a parallax, as normally a parallax is under any tiles you might add. I think a bit more detail of what you are trying to do would be helpful
The parallax is meant to be behind the tileset. If you want it above, you will need an overlay plugin (Yami has a nice one), or a plugin that modifies the location of the parallax, and in that case, it will affect every parallax and map, not just one.