While you are on the edit list, click on the cog icon (1) and four searching options will be displayed: shops, tags, mine and all.
1. Shops: check the "shop" tab (1) and all the shops you have added to your shop list will be shown (2). Uncheck those you don't need at this searching, enter a keyword on the search bar (3) and click on the magnifying glass (4). All the products that match to the terms of this searching will be displayed (5). Click once on the desired products and they will be added to your list.
2. Tags: applying this option will help you to track products you have formerly assigned with tags and you constantly use. Click on "tag" tab (1) and then on tag bar (2). All the tags you have set will be shown. Select as many tags as you want and click on search (4).
It will fetch all the relevant products (5).
Note: If you click on the cog icon nearby the "Tags" (6), you could be able to manage all your tags by editing or deleting them.
Using tags is a quick and effective way of searching the repeated products through your projects.
3. Mine: select the "mine" tab to fetch all the products you have added to your library through the bookmarklet or the "+add product" button. Enter a description on (1) and only the products that respond to that term will be shown.
If you don't enter any description, then, it will bring all the products you have added with the bookmarklet or the +add product button without any exception.
4. All: check this tab (1) for searching to all the above categories concurrently, shops, tags and mine. Enter a term (2) and click on search (3). Select those you want to use with just one click.
Hope this helps!