Groups from Sibling Subsites Visible in Subsite, any way to prevent this?

[Matt Coats]

Hi all, just a question, not an issue. I notice when I make subsites under a parent site, the permission groups from sibling subsites (aka subsites also just under the parent) are visible in the subsite's People and Groups. This isn't breaking anything for us, but I'm curious if there is a way to prevent the groups of subsites from being visible to any given subsite. Is this possible?

[#2 · Accepted solution]

This is actually by design and one of the reasons people use sub sites - to share SharePoint security groups. To prevent this, create unique site collections for discrete units of work (usually a better approach for the long term, especially for governance, which is the issue you raise). If you want to create related families of sites in SharePoint Online, you will soon be able to use Hub sites.