Variations issue

Facing an issue while adding brand & model in a variation I want to sell single product Design (Skin) for different models but I don’t know how to change variation whenever I select brand after model I am not able to change brand once again there is a reference of a website link I am sharing with my issue that I want similar variation style of on my own website skinfymania.com

Variations Type Showing on My product page : https://skinfymania.com/product/2998-trink-brand-mobile-back-skin-layer-paint-smash-print
Variation Type I want on my website (Reference) : https://www.wrapcart.com/collections/best-selling-mobile-skins/products/astro-complex?variant=41807134490779

The page I need help with: [log in to see the link]