“Items” having array of object in each object there is key called “ImpactedCIs” array list. Based on each array list need to generate new object based on “ImpactedCIs” array of objects.

"items": [
        {
            "ImpactedCIs": ["MJUDKHJ112O", "FTTM_ZTF647"],
            "CMSStatus": "5",
            "ActualStartTime": "1700003455",
            "ActualEndTime": "1700003455",
            "PM": "Sample",
            "PMContact": "45345435"
        }
      ]
    
Result: 
"items": [
        {
            "ImpactedCIs": "MJUDKHJ112O",
            "CMSStatus": "5",
            "ActualStartTime": "1700003455",
            "ActualEndTime": "1700003455",
            "PM": "Sample",
            "PMContact": "45345435"
        },
        {
            "ImpactedCIs": "FTTM_ZTF647",
            "CMSStatus": "5",
            "ActualStartTime": "1700003455",
            "ActualEndTime": "1700003455",
            "PM": "Sample",
            "PMContact": "45345435"
        }
    ]