Though you asked for specifics, the first link is, in fact, general: the relationship between father and son in all cases. In all cases, these high profile sons have been deeply influenced by their relationships with their fathers.

Turning to specifics, Hamlet and Laertes both returned to Denmark out of duty. Both want permission to leave again. By contrast, Polonius gives Laertes permission to go, while the king and queen ask Hamlet to stay.

Laertes has no mother present to influence him; Hamlet does. Laertes does have a sister, which Hamlet does not. Both love Ophelia, but in different ways (as a brother vs. sexually).

As for Fortinbras and Hamlet, their fathers fought. The fathers shaped an agreement in which the heir of the other would inherit, if need be, making the sons in some way legally interchangeable. Both think little of Claudius; both lost fathers.