var getSomeData = function(params){ (async function(){

    var users = await APP.accounts.getAll(); // возвращает промис
    for(var k in users){
        params.filter['groups_ids'] = Object.keys(users[k].domains);
        var res = await API.leadList(params, users[k].token);

        if (res.status=='ok') {
            var leads = res.data.leads;
            ...
        }
    }

}()); };