Lo-Fi Games

I'm adding a new building based on the original "OUTPOST IV", and I found the interior mask file is not simply the same shape to the "bravo mask" , it looks like a capsule in the collision viewer. I want to modify it because I changed the XYZ location of the outpost IV.
As some reason, it didn't work correctly when I had created a collision.xml for the mask, the 2nd floor doesn't appear correctly when I went up to the 2nd floor, the top didn't disappear as it should have done.

I am referring to the interior mask file of outpostIV, which uses the "bravo-trigger[NEW].XML", not a collision file created from the "bravo mask.mesh" by blender. I wanna know how to create a .xml like that by my own. Thanks.