Try and if this works for you
code
Manipulate[ {x, y}, Grid[{ {"x", Manipulator[ Dynamic[x, (x = #; If[Abs[x - y] > 1, If[x < 0, y = x + 1, y = x - 1]]) &], {-2,2, .1}]}, {"y", Manipulator[Dynamic[y, (y = #; If[Abs[x - y] > 1, If[y < 0, x = y + 1, x = y - 1]]) &], {-2,2, .1}]} }], {{x, 0}, None}, {{y, 0}, None}, TrackedSymbols :> {x, y} ]