Generally, you can simply get the Distribution Groups or it members by using the following Exchange Cmdlet.

• If we need to get all existing distribution groups, run the Get-DistributionGroup cmdlet.
  
  
  

• If we want to find all distribution group members, use the Get-DistributionGroupMember cmdlet.
  
  
  
  

However, some administrator inquires if we can list all the distribution groups and their members in a single result. Based on our tests, we can use the following scripts to list all existing distribution groups and their members.

foreach ($group in Get-DistributionGroup) { get-distributiongroupmember $group | select Name,@{n='DistributionGroupName';e={$group.Name}} }

If there are too many distribution groups and members, you can export the result to a csv file using the scripts below.

$groupmembers = foreach ($group in Get-DistributionGroup) { get-distributiongroupmember $group | select Name,@{n='DistributionGroupName';e={$group.Name}} }
$groupmembers | Export-Csv C:\DGgroupmembers.csv NoTypeInformation

Then you can find the result in the DGgroupmembers.csv file.

Reference:

Exchange 2007 - enumerate distribution lists members

https://social.technet.microsoft.com/Forums/en-US/1ae1cb17-4fc1-4ac3-824f-dc9c19963f32/exchange-2007-enumerate-distribution-lists-members?forum=exchangesvradminlegacy

Note:

Based on my tests, the above scripts apply to Exchange Server 2007, Exchange Server 2010 and Exchange Server 2013.