regex101: Java Match Workspace

Regular Expression

\"externalLinks\"[\s\S]+?(?=\"maxPop\")

New

"oge": "GOF",
            "original": {
              "report": true,
              "tier": "IA"
            },
            "pertinentNegative": false,
            "populationFrequency": {
              "externalLinks": {
                "7-2-A-T": "https://x.d.org/s/7-d-A-T?dataset=s"
              },
              "maxPop": "South Asian",
              "maxPopAC": 1,
              "maxPopAN": 30,
              "maxPopFreq": 3.276,
              "overallPopAC": 1,
              "overallPopAN": 23,
              "overallPopFreq": 4.22,
              "source": "gnomAD"
            }

Extraction

"oge": "GOF",
            "original": {
              "report": true,
              "tier": "IA"
            },
            "pertinentNegative": false,
            "populationFrequency": {
              "externalLinks": {
                "7-2-A-T": "https://x.d.org/s/7-d-A-T?dataset=s"
              },
              "maxPop": "South Asian",
              "maxPopAC": 1,
              "maxPopAN": 30,
              "maxPopFreq": 3.276,
              "overallPopAC": 1,
              "overallPopAN": 23,
              "overallPopFreq": 4.22,
              "source": "gnomAD"
            }