You can use borders:
h5 {
border-right: 1px solid #dadada;
border-left: 1px solid #dadada;
}
If you want to have space between the lines and the text, you can add padding left and right to the styling:
h5 {
border-right: 1px solid #dadada;
border-left: 1px solid #dadada;
padding: 0 5px;
}
If you want to use the h5 as a nav item and you want to separate it from the rest of the items (the reason you need the divider) you can put the border only on the right, and every next item will inherit the settings.
For the last item, obviously you would want to remove the border right as it doesn't have anything after it, so you can do:
h5 {
border-right: 1px solid #dadada;
}
h5:last-child {
border-right: none;
}