const [unitLeaders, setUnitLeaders] = useState([])

let tags = unitLeaders.map(leader => {

    return <Tag closable={true}

                closeIcon={<CloseCircleOutlined/>}

                onClose={() => clearLeader(leader)}>{leader}</Tag>;

})

<Space wrap>

   {tags}

</Space>

const onClick = ({key}) => {

    setUnitLeaders([...unitLeaders, key])

};

const clearLeader = (leader) => {

    setUnitLeaders(unitLeaders.filter(item => item !== leader))

};

...

let tags = unitLeaders.map(leader => {

    return <Tag closable={true}

                key={leader}

                closeIcon={<CloseCircleOutlined/>}

                onClose={() => clearLeader(leader)}>{leader}</Tag>;

...