Is there any way to add a custom button on the top left corner of a normal Jvectormap? (similar to the back button in a drill-down map).
Create a div as a child of the map, so you can position it relative to the map container:
$("#map").append('<div id="map-action">Action</div>').click(function () {
//do your action here
});
Style it like you want, important here is to set the z-order, so it lies above the map:
CSS:
#map-action {
position: absolute;
left: 10px;
top: 10px;
border-radius: 3px;
z-index: 1000;
background: #292929;
color: #ffffff;
cursor: pointer;
text-align: center;
line-height: 10px;
padding: 6px;
box-sizing: content-box;
}