Draw an area through other objects?

You can use “Translucency Sort Priority” option in detail panel under Rendering category

But this option only work if object has translucent material.
Give your occluding object a translucent material, than set “Translucency Sort Priority” to a value greater than 0 or higher

116442-sortpiority.png

The result :

Purple jelly will always in front of pink jelly!

116443-result.png

Attach a large object (plane is best I think) with a circle transparent material and attach to your player.
The object will follow the player and occlude everything except the transparent area on the object