Stretch to address LBP that affects upper leg of

For a physically active patient with LBP on one side (e.g., right) that leads to tightness and corresponding pain on the leg on the same side of the body (e.g., right), what stretch would you recommend?  The LBP gets worse with the plank exercise or with pushups.  There must be a stretch to address tightness that brings the upper leg near the hip (on the front of the leg) pain when there is corresponding tightness and pain in the lower back on one side.