Modify your Sublimation Templates so they contain more than one image. Use Affinity Designer, or Affinity Photo to place multiple layers containing your images. Then simply select the one you want and export it to the format you want to use to print your sublimation with.
In this case I'm using a 20oz Tapered Latte mug. The image is full size and can be used as it is to print a suitable Mug.