Filters are defined in the themeconfig.json file (your customized version of the siteconfig.json file). They allow you to combine multiple variant outputs within one searchable site.
You need filter labels to select the correct variant output when you navigate in Magellan. You are free to define your own label names and values, there is no direct relationship to Author-it variant criteria names and values.
When you do not want to define any labels, keep the filter_labels entry as follows: