Ah, I see what you mean by it always being in the center. Here is the work around:
If your clip fits the full screen then apply the Displace filter to the clip…other wise to the group that holds the clip. Create a new group. Apply your shockwave. Then move it to where you want it and scale it. As you now it will still place it in the center so here is the work around. If it is on the left create a shape on the right, make sure that shape’s color is black so it will not effect the image. Drag the group that holds the shockwave and the shape into the Displace Filters Map Image. Last, Make sure the group with the shockwave has the Fixed Resolution box checked and then adjust the Fixed Width and Height so it works.
Here is an image that shows “my shockwave” moved to the far left:

Hope this helps and best of luck.
Stephen Smith
Utah Video Productions
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