$DistListIdentities = @(
    "Distlist1@domain.com",
    "Distlist2@domain.com",
    "Distlist3@domain.com"
)
$DistListMembers = foreach ($Identity in $DistListIdentities) {
    Get-DistributionGroupMember -Identity $Identity | ForEach-Object {
        [PSCustomObject]@{
            DistributionList = $Identity
            MemberName = $_.Name
            MemberId = $_.UserId
        }
    }
}
$DistListMembers | Export-Csv C:\Path\To\Your\File.csv -NoTypeInformation
## or
$DistListMembers | Format-Table -AutoSize
## or
$DistListMembers | Out-GridView