A mesne lord was the level of lord in the middle holding several manors, between the lords of a manor and the superior lord.
From the en.wikipedia.org
However, if a mesne lord was involved, then services such as socage, fee and other services might be extracted from the land, either in part or in total.
From the en.wikipedia.org
An overlord was the person from whom a landholding or a manor was held by a mesne lord or vassal under various forms of feudal land tenure.