“dispute.” The Hebrew is rib (#07379 רִיב), and it has a wide range of meanings including strife, controversy, dispute, quarrel, accusation, lawsuit, etc., depending on the context. In this case, “dispute” or “legal dispute” would be good translations because if a person was coming all the way to Jerusalem to the king to get his dispute settled, then it could not be settled by the elders in his hometown, which was usually an easier and quicker way to go. [For more on rib, see commentary on Hosea 4:1].
“the road leading to the gate.” The Hebrew is “the road of the gate.”
“such-and-such a tribe.” In an actual conversation the person would name the tribe, but this was just an example to show how Absalom was acting.