monngoose find from an array using in
//If teamIds is already an array, then you shouldn't wrap it in another array:
Team.find({
'_id': { $in: teamIds }
}, function(err, teamData) {
console.log("teams name " + teamData);
});
//If teamIds is a string of comma-separated id values, you need to convert it into an array of values using split:
Team.find({
'_id': { $in: teamIds.split(',') }
}, function(err, teamData) {
console.log("teams name " + teamData);
});