I am building flutter app and using firestore. would like to give the user the capability to do some filtering on the data. so he will be selecting some filters and providing values to specific fields to be matched with the stored data in the firestore. the only way I can think of is something like building a stream builder with a stram like the below then when the user select the filter I add the value to the variable, and if filter not selected, the variable value should be equal to "Any". how can I represent this "Any" with firestore? or is there a better solution than this?
StreamBuilder<QuerySnapshot>(
stream: FirebaseFirestore.instance
.collection('PropertiesCollection')
.orderBy('Property_date', descending: true)
.where('Property_license', isEqualTo: variable1)
.where('Property_city', isEqualTo: variable2)
.where('Property_service', isEqualTo: variable3)
.snapshots(),