AFAIK there is no way to query special structured information for a given file.
What you could do is to access the information in the Structure pane. That way requires the file to be the active module (can be achieved by the OTA), the output depends on the Structure pane settings (Tools | Options... -> Environment Options | Explorer) and if a node is a field, a procedure or whatever needs to be determined over the image index, parent...
This code walks through the Structure pane.
procedure StructureViewToSL(ASL: TStringList);
procedure TreeToSL(ANode: IOTAStructureNode; ASL: TStringList; const APrefix: string);
var
I: Integer;
begin
ASL.Add(APrefix + ANode.Caption);
for I := 0 to ANode.ChildCount - 1 do
TreeToSL(ANode.Child[I], ASL, APrefix + ' ');
end;
var
StructureView: IOTAStructureView;
StructureContext: IOTAStructureContext;
Node: IOTAStructureNode;
I: Integer;
begin
StructureView := BorlandIDEServices as IOTAStructureView;
StructureContext := StructureView.GetStructureContext;
for I := 0 to StructureContext.RootNodeCount - 1 do
begin
Node := StructureContext.GetRootStructureNode(I);
TreeToSL(Node, ASL, '');
end;
end;