MultiSelect.js

import {Dropdown} from 'react-bootstrap';
import {SelectList} from 'react-widgets';

const selectData = ['Red', 'Blue', 'Green'];

export default class extends Component {

  constructor(props) {
    super(props);
    this.state = {
      selectedColors: []
    };
  }

  onValueChange = (values) => {
    this.setState({selectedColors: values});
  }
  render() {
    const {selectedColors} = this.state;
    const selectListLabel = selectedColors.length ? selectedColors.join(', ') : 'Select a Color';
    return (
      <Dropdown id="multiselect">
        <Dropdown.Toggle>
          {selectListLabel}
        </Dropdown.Toggle>
        <Dropdown.Menu>
          <div onClick={(e) => e.stopPropagation}>
            <SelectList data={selectData} multiple 
              value={selectedColors} 
              onChange={this.onValueChange} 
              style={{border: 'none'}}/>
          </div>
          </Dropdown.Menu>
      </Dropdown>
    );
  }
}