To find first word of a sentence in mongodb of specified size

I want to find the first word from a sentence(phrase) whose size is less than 3 letters.Is there any way i could find it? please suggest.

I have used

 .map(function(st){return st.split(" ")[0];} 

function it gives me all the first words in array format.But this is not the expected output.

{ "name" : "VAS LAYER BREED FARM PRIVATE LIMITED" }

{ "name" : "UTTARA BROILER BREED FARM PRIVATE LTD" }

{ "name" : "SAI REKHA POULTRY PRIVATE LTD" }

{ "name" : "RUHITECH NUTRITION PRIVATE LTD" }

{ "name" : "SADKAR BROILER AND AGRO FARMS PRIVATE LTD" }

{ "name" : "SADAR POULTRY PRIVATE LTD" }

From this list i need the output to print only the words: ("SAI","VAS") in the output.

You may perform aggregation query.

db.collection.aggregate([
  {
    $project: {
      name: {
        $let: {
          vars: {
            first: {
              $arrayElemAt: [
                {
                  $split: [
                    "$name",
                    " "
                  ]
                },
                0
              ]
            }
          },
          in: {
            $cond: [
              {
                $lte: [
                  {
                    $strLenCP: "$$first"
                  },
                  3
                ]
              },
              "$$first",
              ""
            ]
          }
        }
      }
    }
  },
  {
    $match: {
      name: {
        $ne: ""
      }
    }
  },
  {
    $group: {
      _id: null,
      name: {
        $push: "$name"
      }
    }
  }
])

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