public static KnowledgeGraphInvestigationView Active {get;}

// access the currently active knowledge graph investigation view
KnowledgeGraphInvestigationView activeView = KnowledgeGraphInvestigationView.Active;
KnowledgeGraphInvestigation investigation = activeView?.Investigation;
if (investigation != null)
{
  // perform some action
}

// get the active investigation view
var iv = KnowledgeGraphInvestigationView.Active;

// clear any TOC selection
iv.ClearTOCSelection();

// select entities
List<string> entities = new List<string>();
entities.Add("Person");
entities.Add("Org");
iv.SelectEntities(entities);

// or select relationships
List<string> relationships = new List<string>();
relationships.Add("HasEmployee");
iv.SelectRelationships(relationships);

// or select a combination
List<string> namedObjectTypes =  new List<string>();
namedObjectTypes.Add("Person");
namedObjectTypes.Add("Org");
namedObjectTypes.Add("HasEmployee");
iv.SelectNamedObjectTypes(namedObjectTypes);

// get the active investigation view 
var iv = KnowledgeGraphInvestigationView.Active;
var serviceUri = iv.Investigation.ServiceUri;

// build a dictionary of records
var dict = new Dictionary<string, List<long>>();
//Each entry consists of the type name and corresponding lists of ids
dict.Add(first_entity, new List<long>() { 1, 5, 18, 36, 78 });

//Create the id set...
var idSet = KnowledgeGraphLayerIDSet.FromDictionary(new Uri(serviceUri), dict);

// select the records on the investigation view
iv.SetSelectedRecords(idSet, SelectionCombinationMethod.New);

// get the active investigation view
var iv = KnowledgeGraphInvestigationView.Active;

QueuedTask.Run(() =>
{
  // get the investigation
  var inv = iv.Investigation;

  // get the set of selected records
  var idSet = iv.GetSelectedRecords();

  // view these records in a link chart
  var map = MapFactory.Instance.CreateLinkChart("myLinkChart", new Uri(inv.ServiceUri), idSet);
  ProApp.Panes.CreateMapPaneAsync(map);
});