The picture you posted is Johnson hardware. The hole with the screw is the pivot/adjustment. The other with the rubber/screw is the bumper that goes at the other end. You should have 3 pins that go into the bifold unit. One should have a screw adjustment on it, that goes in the bottom of the door for the bottom pivot. You should have to pins that are spring loaded with a plastic disk on it that goes into the pivot and track-use one for the top pivot and the other goes into the leading door at the top. Withe the door closed, the leading door pin should be against the rubber snubber, it should be adjusted so the door sort of snaps into place in a straight line. You should also have an L type bracket that is fastened at the bottom of the jamb for the bottom pivot. It should have a screw with a plastic insert in it. The screw adjustment pin fits into it. You can adjust the door for clearance by sliding the top and/or bottom pivot holders. The screw pivot will raise the door unit up or down.
