How to control popover-arrow position in bootstrap 4

You can adjust the position of the arrow with the following styles:

Bootstrap 3

.popover.bottom > .arrow {
    margin-left: 50px;
}

Bootstrap 4

.popover.bs-tether-element-attached-top::after,
.popover.bs-tether-element-attached-top::before{
    left: 65%;
}