Adv. Disp. Landscape Materials
A Tessellated Displacement material designed specifically for use with Landscape Actors which allows you to blend between 3 'texture sets', the material also allows you to adjust parameters for each 'texture set' individually via instanced values. The setup of this material fixes the issues caused by using a standard tessellation material on a Landscape Actor and allows you to control LOD of the tessellation without interfering with the Landscape Actor's own LOD.
More Info: _https://www.unrealengine.com/marketplace/adv-disp-landscape-materials