I created a simple sample that shows some basic FireDAC functionality with MongoDB in C++ (Works with C++Builder or RAD Studio 10 Seattle)
This is similar to a one of the Object Pascal / Delphi MongoDB sample. It shows how you can query a MongoDB database using the new TFDMongoQuery component and display it in a grid. It also shows how to handle nested document objects (like Address) and arrays / DataSets (Address.Coords and Grades).
In addition to using the match property of the query, it also allows the specification of a sort and a projection. The projection is used to change which fields of the document you retrieve.