How to strip document owner permissions

[EverGrateful]

Hello all,

Question about a potential approach for you.

Due to the type of data structure being dealt with we have employed a SPO site consisting of numerous document libraries with rather granular permissions.   Directory permissions are broken down by synchronized AD groups.  I understand that this is skirting around the preferred handling of permissions  within SPO but I am dealing with the restrictions in place. 

Since the permissions are granular and have been migrated over using SPMT documents still retain their unique permissions.  What I would like to know is - is there a possible way to strip document owner permissions if someone has been removed from the overlying group?  

Thank you for your help

[#2]

Hello @EverGrateful 

it's not clear for me, what you want to know: "is there a possible way to strip document owner permissions if someone has been removed from the overlying group? "

You can use PowerShell or Flows to set item level permissions. Pls attention about limits and boundaries: https://learn.microsoft.com/en-us/sharepoint/troubleshoot/lists-and-libraries/error-share-break-inhe... 

"The supported limit of unique permissions for items in a list or library is 50,000. However, the recommended general limit is 5,000. Making changes to more than 5,000 uniquely permitted items at a time takes longer. Therefore, for large lists, design the list to have as few unique permissions as possible"

Regards, Dave

[#3]

David,
Thank you for your reply.
What I mean is that we would like to remove access to document level Owner permissions when a user is removed from a group which has access to specific DLs/Directories/Documents.
Due to the fact file share permissions were preserved with the migration, pre-existing documents have unique owner permissions and do not inherit permissions from the directory above.

We would like to strip these owner permissions once access to the DL or Directories within which the docs are housed is removed.