Having trouble with slicing this image

So basically I’m trying to make a design for all of my borders, it’s an image that goes on top of a frame for a cool design.

Heres the image:
TopBorder Try
So I want to slice it properly but It ends up looking like this
image
I want to achieve the warping style so my border stretches properly and doesn’t mess up the middle design(the dot and square)

Can anyone assist me with this?