I have applied solr facet on properties of products.
Eg: The product can be either Medicine(0/1) or Drug(0/1) or Poison(0/1). 0 means NO, 1 means YES.
These are different features of a product hence appear as different facets. It is possible to display them under one facet instead eg: "Type", under which these three solr facet "Medicine", "Drug", "Poison" should display like:
Type ----- Medicine (50) Drug (100) Poison (75)