More examples in xmldetails.md please about vsts-extension-multivalue-control HOT 2 CLOSED

The "Id" is the name which identifies the input. This is used in the extension internally. You must not change it.

The ref name of your field is "MyNamespace.MyField".

So your input tag should look like this:
<Input Id="FieldName" Value="MyNamespace.MyField" />

The items are taken from the AllowedValues list. So, yes, this is the same as in previous versions.

from vsts-extension-multivalue-control.

@FlexiGit Is correct. This extension defines two inputs ids FieldName and Values. For FieldName you make the value the reference name of the field. If you only specify this, then the extension will try to use that fieldName to also get the list of values from its Suggested value list. If you also specify values then it will use that list for the values to populate the control

from vsts-extension-multivalue-control.