using Newtonsoft.Json.Linq;

using System;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        string json = @"[

        {

        'fieldName': 'Gender',

        'selector': 'custom.gender2',

        'action': 'UPDATE|REMOVE',

        'value': 'string',

        'allowedValues': [

            'Unknown',

            'Male',

            'Female',

            'No Disclosure'

        ],

        'tab': {

            'id': 103,

            'title': 'Details'

        },

        'fieldset': {

            'id': 423,

            'title': 'Physical Characteristics'

        },

        'limitByPersonType': [

            2019,

            2021,

            2022,

            2023,

            2025,

            2027,

            2028,

            2105,

            2106,

            2133

        ],

        'examples': [

            {

                'selector': 'custom.gender2',

                'action': 'UPDATE',

                'value': 'Unknown'

            },

            {

                'selector': 'custom.gender2',

                'action': 'REMOVE'

            }

        ]

    },

    {

        'fieldName': 'Hair Color',

        'selector': 'custom.hairColor',

        'action': 'UPDATE|REMOVE',

        'value': 'string',

        'allowedValues': [

            'Bald',

            'Black',

            'Blonde',

            'Brown',

            'Gray',

            'Multicolored',

            'Red',

            'White'

        ],

        'tab': {

            'id': 103,

            'title': 'Details'

        },

        'fieldset': {

            'id': 423,

            'title': 'Physical Characteristics'

        },

        'limitByPersonType': [

            2019,

            2022,

            2023,

            2027,

            2106

        ],

        'examples': [

            {

                'selector': 'custom.hairColor',

                'action': 'UPDATE',

                'value': 'Bald'

            },

            {

                'selector': 'custom.hairColor',

                'action': 'REMOVE'

            }

        ]

    }

    ]";

        string tabName= "tab";

        string tabTitle= "Details";

        JArray jAry = JArray.Parse(json);

        var tabId = jAry

            .Where(j => j[tabName]["title"].ToString() == tabTitle)

            .Select(j => (int)j[tabName]["id"])

            .FirstOrDefault();

        Console.WriteLine("Id = " + tabId);

     }

}

​