Xml documentation doesn't have a means to reference all overloads of a method.
The most popular documentation generator for C# projects is Sandcastle. It will automatically create a link to an overloads list page if necessary. Hence in a members list page the name of an overloaded method will appear only once, clicking it will navigate you to the list of overloads page for that method and from there to a specific overload.
Placing a link to the overloads list page in Xml documentation would require intimate knowledge of the external tool being used and probably not a good idea.
If you really must have this then perhaps one way is to use an anchor with a specificaly formed ID. Most document generators provide some arcane means of pre or post processing generated files and should give you the opportunity to pick these anchors out and provide an appropriate href for them.
OTH, it may be more trouble than its worth ;)