You seem to describe this data model:
Clients::__pkClientID = ClientQueries::_fkClientID
ClientQueries::__pkClientQueryID = Notes::_fkClientQueryID
Then a portal to Notes placed on a Clients layout would show all notes for all client queries associated with that client.
Don't quite see why you would want that in one field, but a calculation field defined in Clients could use either the List or ExecuteSQL function to list all (or a selected subset) notes for that client in a single field.
For an explanation of the notation that I am using, see the first post of: Common Forum Relationship and Field Notations Explained