[Vuejs]-How to bind value of a button in vuejs?

You can do it like

<b-button-group>
     <b-btn value="one"  @click="stateButtons = "one">one</b-btn>
     <b-btn value="two" @click="stateButtons = "two">two</b-btn>
     <b-btn value="three" @click="stateButtons = "three">three</b-btn>
</b-button-group>

Bootstrap button group doesn’t allow any v-model attribute so you can do it manually like

  <b-button-group >
      <b-btn @click="stateButtons = 'one'">one</b-btn>
      <b-btn  @click="stateButtons = 'two'">two</b-btn>
      <b-btn @click="stateButtons = 'three'">three</b-btn>
    </b-button-group>

    <p>Chossen: {{stateButtons}}</p>