In the classic client it was a requirement from a lot of end-users to easily count filtered records in a listform. This can be solved by adding a control with SourceExpr COUNT on the form.
Off course we should watch for performance but with Master Data this should not be an issue.
But now we have pages, so how can we implement that? It's not wysiwyg. Where do I put the control.
This is what I did:
In the List Page search for the end of the group repeater and add a new group group. In this group add a field with SourceExpr Count and add some captions.
This is the result:
This is just what I experimented and implemented, it is not supported by Microsoft!