Evidence: <Where><Geq> on ID at 5495 (the newest item id 5500 less 5), with LVChoice: Indexed=false, AutoIndexed=false. The counter spelling was tried rather than assumed: Type="Counter": HTTP 200, SERVED (6 row(s)), so Type="Counter" is what answered. The same filter with no <GroupBy> returned 6 row(s) naming ["dbmlsp-lv-05495.txt","dbmlsp-lv-05496.txt","dbmlsp-lv-05497.txt","dbmlsp-lv-05498.txt","dbmlsp-lv-05499.txt","dbmlsp-lv-05500.txt"], a count READ rather than predicted because item ids need not be contiguous. collapsed HTTP 200 returned 4 row(s) against a RowLimit of 100, labels ["Alpha","Beta","Delta","Gamma"], grouping markers ["LVChoice.COUNT.group","LVChoice.newgroup","LVChoice.groupindex"], first row {"LVChoice":"Alpha","LVChoice.urlencoded":"%3B%23Alpha%3B%23","LVChoice.singleurlencoded":"Alpha","LVChoice.COUNT.group":"2","LVChoice.newgroup":"1","LVChoice.groupindex":"1_","PreviewThumbnailsQualitySets":""}; expanded HTTP 200 returned 6 row(s); the same query with no <GroupBy> returned HTTP 200 with 6 row(s); ViewXml <View><Query><Where><Geq><FieldRef Name="ID"/><Value Type="Counter">5495</Value></Geq></Where><GroupBy Collapse="TRUE"><FieldRef Name="LVChoice"/></GroupBy></Query><ViewFields><FieldRef Name="FileLeafRef"/><FieldRef Name="LVNumber"/><FieldRef Name="LVChoice"/></ViewFields><RowLimit>100</RowLimit></V. The values those filtered rows hold, off the expanded query, are ["Alpha","Beta","Delta","Gamma"] and the collapsed labels are ["Alpha","Beta","Delta","Gamma"]. The group was built over the rows the filter kept, so a filtered view groups what it shows. Read this beside library.view.filter-with-group-by, which measured the same composition on a library of six files.