How do I see only the products from one category, brand or price range in the admin?

Use the filter panel on the product list.

1. Go to Products → Products and click Filters.
2. In the panel, choose a Category and/or a Brand.
3. Under Price range, enter a minimum and/or a maximum.
4. You can also filter by Status, Type and Stock.

Each active filter shows as a chip under the search bar, such as "Category: Footwear" or "Price: 0–1000". Click the × on a chip to remove that filter, or Clear all to remove them all. The number on the Filters button shows how many filters are on.