Filtering Icons and Bundles in D3M is a very simple process. At the top of your enabled libraries, there is a filter button. Clicking on the button will open your filtering options. You can then choose to filter by Icons & Bundles, Only Icons, Only Bundles, or by size of icons.
This feature enables you to filter your icon library in order to best fit your needs for projects / tasks. It also helps you find the icons or bundles that you are looking for more efficiently.
That's all there is to it! Check out some other help articles that go into detail about using icons & bundles within D3M.