Find document position in result after aggregation

[Ashish_20501 (Ashish Karambalkar)]

Find position of document in aggregation result and add it in same output
e.g

i want deliveredUnits 12 position to 2 with newly added field in same collection
with mongodb version 4.4 version

[Pavel_Duchovny]

Hi @Ashish_20501 ,

What you want is $rank available only from 5.0 .

$rank (aggregation) — MongoDB Manual

For 4.4 there is tricks for ranks and dense rank :

Rank and Dense Rank in Aggregation

Thanks
Pavel