JSFiddle - React, Tailwind, and code Playground

HTML

Texts: <span data-bind="text: Texts()"></span>
<hr />
<a data-bind="click: changeSelectedFormat" href="#">
    <span>Click to change to another selectedFormat value</span>
</a>

JavaScript

window.vm = {
    selectedFormat: ko.observable({
        Texts: ko.observable("One")
    })
};

vm.Texts = ko.computed(function () {
  var self = vm;
  if (self.selectedFormat()) {
    return self.selectedFormat().Texts();
  }
});

vm.changeSelectedFormat = function() {
    vm.selectedFormat({ Texts: ko.observable("Two") })
};

ko.applyBindings(vm);