Suggested method to update value in object literal from promise callback

I realize there are probably 10 ways to do this and I typically stumble through some clumsy way to achieve it - however I'd like to get a couple of ideas on "clean" ways to update a value in an object literal from a promise callback.

My current use case is:

let groups2 = {
    groupsList: [],
    updateGroups: () => {
        return axios({
            'url': 'https://gitlab.com/api/v3/groups?per_page=500',
            'method': 'GET',
            'headers': {
                'private-token': GITLAB_API_PRIVATE_TOKEN,
                'cache-control': 'no-cache'
            }
        })
        .then(function (response) {
            console.log(response);
            groups2.groupsList = response.data;
        })
        .catch(function (error) {
            console.log(error);
        });
    }
}

This works, however it "feels bad?" to reference "groups2" specifically from inside itself (in the callback in this case). Essentially I want a singleton that can operate on it's own values via functions that may contain promises. I'm looking for better ideas on how to do it.

via MPT