db={"locations":[{"_id":"622b6f1c7a0aca9aa252756c","country":"US","county":"Florida","city":"Miami","lType":"base","displayString":"Florida,Miami","__v":0},{"_id":"622b6f1d7a0aca9aa252756e","landmark":"Gas station","baseLocation":"622b6f1c7a0aca9aa252756c","lType":"extra","displayString":"Florida,Miami,Gas station","__v":0},{"_id":"622b6f4c5d0fe602a18826a7","country":"US","county":"Florida","city":"Tampa","lType":"base","displayString":"Florida,Tampa","__v":0},{"_id":"622b6f4c5d0fe602a18826a9","landmark":"Downtown","baseLocation":"622b6f4c5d0fe602a18826a7","lType":"extra","displayString":"Florida,Tampa,Downtown","__v":0}]}

db.locations.aggregate([{"$lookup":{"from":"locations","localField":"baseLocation","foreignField":"_id","as":"locationData"}}])