function postProcessMultiple_(template, select, instanceStr) {
  domSetAttribute(template, ATT_select, select);
  domSetAttribute(template, ATT_instance, instanceStr);
}
Sets ATT_select and ATT_instance following recursion to jstProcess.

@param {Element} template  The template

@param {String} select  The jsselect string

@param {String} instanceStr  The new value for the jsinstance attribute