Thanks Kazun. It's working.
Dear all,
I've the other question,
I've created ABC DEF distribution group in 123 domain, and added some users into this group, some users come from 123 domain, some users come from 789 domain.
If I run the below script
Get-DistributionGroupMember -identity "ABC DEF" -ResultSize Unlimited | export-csv -NoTypeInformation -path .\ExportGroupMemberLists.csv -encoding utf8
There can be found 123 domain users only from the csv file, I cannot find any 789 domain users.
Then I go to ADUC to check this distribution group, I can see 123 & 789 domain users inside.
Why? PLs help, many many thanks.!