If you mean a link in a form (like DispForm) to open maps.google.com you can use a few lines of custom code like this.
Add this HTML to a HTML section in a tab:
<div id="mapsLinkPlaceholder"></div>
Then add this to your Custom JS:
function getMapsLink(){
var b = [], lat = getFieldValue("Lat"), long = getFieldValue("Long");
b.push("<a href='http://www.google.com/maps/place/"+lat+","+long+"' target='_blank'>");
b.push("<img src='https://www.gstatic.com/images/branding/product/1x/maps_64dp.png'>");
b.push("</a>");
jQuery("#mapsLinkPlaceholder").html(b.join(""));
}
// Call directly, or from a rule
getMapsLink();
Change the field names “Lat” and “Long” to match your field names.
Alexander