How do I filter posts using the Taxonomy filter?

1. In Search, click the Filter button and then scroll down and select Taxonomy in the filter menu.
2. Tick boxes in the Taxonomy fields to filter posts. 
3. The search result is displayed in the post list.

Selecting several topics in the same field creates an OR question between them, making a wider search. When selecting topics from different fields, an AND question is created, making a narrower search.