Database
[{"_id":"60035d0a1599912a5c814e58","idUsuario":"600365521599912a5c814e5e","parentNode":"","piernaPadre":"","estado":"1"},{"_id":"6003827b06b4423c9ca7e6aa","idUsuario":"60036e53dda7df34749ebf3a","parentNode":"60035d0a1599912a5c814e58","piernaPadre":"d","estado":1},{"_id":"60038c92ea7d593fe029cc0f","idUsuario":"600382a506b4423c9ca7e6ab","parentNode":"6003827b06b4423c9ca7e6aa","piernaPadre":"d","estado":1}]
Query
db.collection.aggregate([{$match:{parentNode:""}},{$graphLookup:{from:"collection",startWith:"$_id",connectFromField:"_id",connectToField:"parentNode",as:"arrayDes"}}])