Options After Select More Options

[salchisal]

After selecting the first option, I want the transform options according to the first option to appear when I select more options.

For two products with different variant options, we want the options for those products to change automatically.

ex) 1 option >> t-shirts /pants

      2 option>>  S,M,L   / 27, 28, 29 

   select [t-shirts]> [S, M, L]  or 

   select [pants]> [27, 28, 29]  

In this way, I want the 2nd option to automatically show the transformation option according to the 1st option.

Below is the code I did.

I'm sorry that it's hard to understand because I'm not good at English. .  .