.wrap-cont {
  display: flex;
}
.item {
  width: 300px;
  height: 300px;
}
.item:nth-child(1) {
  background-color: crimson;
}
.item:nth-child(2) {
  background-color: blue;
  position: relative;
  top: 200px;
  left: -100px;
}
.item:nth-child(3) {
  background-color:chartreuse;
  position: relative;
  top: 400px;
  left: -200px;
  z-index: -1;
}