TotalCount  PartyId     DisplayName EmailAddress      PhoneNumber
-----------------------------------------------------------------
3           1           Sarah       sarah@gmail.com   1
3           1           Sarah       sarah2@gmail.com  1
3           1           Sarah       sarah@gmail.com   2

DECLARE @CurrentPage int = 1
DECLARE @PageSize int = 1000

SELECT
    COUNT(*) OVER () as TotalCount,
    p.Id AS PartyId,
    e.EmailAddress,
    pn.PhoneNumber
    etc.....
FROM
    [dbo].[Party] AS p WITH(NOLOCK)
INNER JOIN
    [dbo].[Email] AS e WITH(NOLOCK) ON p.[Id] = e.[PartyID]
INNER JOIN
    [dbo].[PhoneNumber] AS pn WITH(NOLOCK) ON p.[Id] = pn.[PartyID]
    etc.....
WHERE
    p.PartyType = 1 /*Individual*/
GROUP BY
    p.Id, e.EmailAddress, pn.PhoneNumber etc...
ORDER BY
    p.Id
    OFFSET (@CurrentPage - 1) * @PageSize ROWS
    FETCH NEXT @PageSize ROWS ONLY

var responseModel = unitOfWork.PartyRepository.SearchContacts(model);

if (responseModel != null && responseModel.Count == 0)
{
    return null;
}

// get multiple phones/emails for a party
var emailAddresses = responseModel.GroupBy(p => new { p.PartyId, p.EmailAddress })
                            .Select(x => new {
                                    x.Key.PartyId,
                                    x.Key.EmailAddress
                            });

var phoneNumbers = responseModel.GroupBy(p => new { p.PartyId, p.PhoneNumber, p.PhoneNumberCreateDate })
                            .Select(x => new {
                                    x.Key.PartyId,
                                    x.Key.PhoneNumber,
                                    x.Key.PhoneNumberCreateDate
                            }).OrderByDescending(p => p.PhoneNumberCreateDate);

// group by in order to avoid multiple records with different email/phones
responseModel = responseModel.GroupBy(x => x.PartyId)
                   .Select(grp => grp.First())
                   .ToList();

var list = Mapper.Map<List<SearchContactResponseModelData>>(responseModel);

// add all phones/emails to respective party
list = list.Select(x =>
                    {
                        x.EmailAddresses = new List<string>();
                        x.EmailAddresses.AddRange(emailAddresses.Where(y => y.PartyId == x.PartyId).Select(y => y.EmailAddress));

                        x.PhoneNumbers = new List<string>();
                        x.PhoneNumbers.AddRange(phoneNumbers.Where(y => y.PartyId == x.PartyId).Select(y => y.PhoneNumber));
                        return x;
                    }).ToList();

var sorted = SortAndPagination(model, model.SortBy, list);

SearchContactResponseModel result = new SearchContactResponseModel()
            {
                Data = sorted,
                TotalCount = list.Count
            };

return result;

{
  "TotalCount": 1,
  "Data": [
    {
      "PartyId": 1,
      "DisplayName": "SARAH",
      "EmailAddresses": [
        "sarah@gmail.com",
        "sarah2@gmail.com"
      ],
      "PhoneNumbers": [
        "1",
        "2"
      ]
    }
  ]
}

DECLARE @CurrentPage int = 1;
DECLARE @PageSize int = 1000;

WITH PartyList AS (
    SELECT
        COUNT(*) OVER () as TotalCount,
        p.Id AS PartyId
    FROM
        [dbo].[Party] AS p WITH(NOLOCK)
    WHERE
        p.PartyType = 1 /*Individual*/
    GROUP BY -- You might not need this now depending on your data
        p.Id
    ORDER BY
        p.Id
        OFFSET (@CurrentPage - 1) * @PageSize ROWS
        FETCH NEXT @PageSize ROWS ONLY
)
SELECT
    pl.TotalCount,
    pl.PartyId,
    e.EmailAddress,
    pn.PhoneNumber
FROM PartyList AS pl
    INNER JOIN
        [dbo].[Email] AS e WITH(NOLOCK) ON pl.[PartyId] = e.[PartyID]
    INNER JOIN
        [dbo].[PhoneNumber] AS pn WITH(NOLOCK) ON pl.[PartyId] = pn.[PartyID];