By default, you can create a maximum of 400 Groups per Perspective in the platform.
Be careful to not represent every unique attribute of your infrastructure as a Group name as it could make reports overly complex and unintuitive as well as potentially hit your 400 group limit. Hitting the group limit will result in all additional groups to not be allocated or represented in reports. For instance, if you create a perspective with a result that would give you 500 unique groups, the perspective would only allocate 400 of those and the remaining 100 groups and their assets would not be referenced.
While the platform does have the capability to manually raise the group limit on a per-perspective basis, it's always recommended to double-check your limits to ensure you aren't maxing out. Proper perspective maintenance and clean-up will help avoid this issue as well.