Active Directory Attributes and Dynamic Distribution groups
Solution 1:
Where is the roomNumber filled in? Are all roomnumbers of the redbuilding the same?
And If the roomnumber is filled in office , try typing below command in EMS
New-DynamicDistributionGroup -Name "Bluebuilding" -RecipientFilter {office -eq 'blue'}
New-DynamicDistributionGroup -Name "Redbuilding" -RecipientFilter {office -eq 'red'}
Note:red means the roomnumber of the redbuilding