public Object3DRenderingMode FilterBlockMode {get; set;}

//var bsl = ...;
//Note: wire_frame_filters can be null in this example
var wire_frame_filters = bsl.GetFilters().Where(
  f => f.FilterBlockDefinitions.Any(
    fb => fb.FilterBlockMode == Object3DRenderingMode.Wireframe));
//substitute Object3DRenderingMode.None to get blocks with a solid mode (default)
//and...
//fb.FilterBlockMode == Object3DRenderingMode.Wireframe &&
//fb.FilterBlockMode == Object3DRenderingMode.None
//for blocks with both

//Must be called on the MCT

//refer to "Query Building Scene Layer for available Types and Values"
//...
//var bsl = ...;
//At 2.x
//var dict = bsl.QueryAvailableFieldsAndValues();

//var dict = bsl.GetAvailableFieldsAndValues();
//var categories = dict.SingleOrDefault(kvp => kvp.Key == "Category").Value;
//var floors = dict.SingleOrDefault(kvp => kvp.Key == "BldgLevel").Value;

//Make a new filter definition
var fd = new FilterDefinition()
{
  Name = "Floor and Category Filter",
  Description = "Example filter",
};
//Set up the values for the filter
var filtervals = new Dictionary<string, List<string>>();
filtervals.Add("BldgLevel", new List<string>() { floors[0] });
var category_vals = categories.Where(v => v == "Walls" || v == "Stairs").ToList() ?? new List<string>();
if (category_vals.Count() > 0)
{
  filtervals.Add("Category", category_vals);
}
//Create a solid block (other option is "Wireframe")
var fdef = new FilterBlockDefinition()
{
  FilterBlockMode = Object3DRenderingMode.None,
  Title = "Solid Filter",
  SelectedValues = filtervals//Floor and Category
};
//Apply the block
fd.FilterBlockDefinitions = new List<FilterBlockDefinition>() { fdef };
//Add the filter definition to the layer
//At 2.x - bsl.SetFilter(fd);
bsl.UpdateFilter(fd);
//Set it active. The ID is auto-generated
bsl.SetActiveFilter(fd.ID);

//Must be called on the MCT
//Assuming retrieve filter ok
//var bsl = ...;
//var filter1 = bsl.GetFilter(...);

var filterBlock = new FilterBlockDefinition();
filterBlock.FilterBlockMode = Object3DRenderingMode.Wireframe;
        
var selectedValues = new Dictionary<string, List<string>>();
//We assume QueryAvailableFieldsAndValues() contains "Walls" and "Doors"
//For 'Category'
selectedValues["Category"] = new List<string>() { "Walls", "Doors" };
filterBlock.SelectedValues = selectedValues;

//Overwrite
filter1.FilterBlockDefinitions = new List<FilterBlockDefinition>() { filterBlock };
//At 2.x - bsl.SetFilter(filter1);
bsl.UpdateFilter(filter1);