I am trying to fetch a collection' data called highlights that has a doc and another collection ,
I want to retrieve only the data :

const fetchHighlight =async()=>{
const HighlightDbId = await db.collection('highlights').doc('2SCS2S0JnzngWEiYkHNk')
.collection('hBYWvZ3KN3NLLrucTpryeTQZnHz2').get()
console.log(HighlightDbId)
}
React.useEffect(()=>
{
fetchHighlight ()
}, [])
How can I retrieve this collection's data (tag,teamColor, team ...)
This is what I get when i console log :

There are good hands on examples for all the basic cases such as this one. In your code, you get the snapshot of the collection query right, but you need to iterate docs on in snapshot object.
Look for more in here: https://firebase.google.com/docs/firestore/query-data/get-data#get_multiple_documents_from_a_collection.