where​

{{where array key [value]}}

{{ assign 'filter_products' (where collection.products 'vendor' "Natural Threads") }}
Products from Natural Threads:
{{#each filter_products as |product| }}
  - {{ product.title }}
{{/each}}

{{ assign 'available_products' (where collection.products 'available') }}
Available products:
{{#each available_products as |product| }}
  - {{ product.title }}
{{/each}}