diff --git a/class/ExpressionBuilder.php b/class/ExpressionBuilder.php
index 47ab51d..87776d2 100644
--- a/class/ExpressionBuilder.php
+++ b/class/ExpressionBuilder.php
@@ -20,6 +20,8 @@ class ExpressionBuilder
             } else { // is it a float?
                 return (double)$rval;
             }
+        } else if (in_array(strtolower($rval), ["true", "false"]) ) { // it's a boolean
+            return $rval === "true";
         } else if (str_starts_with($rval, '"') && str_ends_with($rval, '"')){ // it's a string
             return substr($rval, 1, strlen($rval) - 2); // strip leading and trailing quotes
         } else { // it must be a column name
diff --git a/class/GroupMgr.php b/class/GroupMgr.php
index c3cc548..eca14e3 100644
--- a/class/GroupMgr.php
+++ b/class/GroupMgr.php
@@ -403,4 +403,17 @@ class GroupMgr
         $a = $qb->where(["games", "CONTAINS", (int)$gameid])->select(["_id"])->getQuery()->fetch();
         return array_map(fn($r) => $r["_id"], $a);
     }
+
+    // Get group by group compound (name#id).
+    function getGroupByUniqueName(string $uniqueName): Group|null {
+        $a = $this->db->findOneBy([ function($g) use ($uniqueName) : bool {
+            $group = Group::fromArray($this, $g);
+            return $group->getUniqueName() === $uniqueName;
+        }]);
+        if ($a !== null) {
+            return Group::fromArray($this, $a);
+        } else {
+            return null;
+        }
+    }
 }
\ No newline at end of file
diff --git a/class/TestMgr.php b/class/TestMgr.php
index 04c61af..e4729d1 100644
--- a/class/TestMgr.php
+++ b/class/TestMgr.php
@@ -400,7 +400,7 @@ class TestMgr
     }
 
     // Get test results by game ID.
-    function getResultsByGameId(string $gameid, string $filter, string $orderby, bool $exclude_challenge_data): array
+    function getResultsByGameId(string $gameid, string $filter, string $orderby, bool $exclude_challenge_data, array ...$furtherFilters): array
     {
         $qb = $this->db->createQueryBuilder();
         $qb = $qb->where(["gameid", "=", (int)$gameid]);
@@ -417,9 +417,19 @@ class TestMgr
             }
 
             $criteria = ExpressionBuilder::buildQuery($filter);
+
             $qb->where($criteria);
         }
 
+        // add further filters
+        if (count($furtherFilters) > 0) {
+            foreach ($furtherFilters as $ff) {
+                if ($ff !== []) {
+                    $qb->where($ff);
+                }
+            }
+        }
+
         // ordering
         if (trim($orderby) !== "") {
             $ordering = ExpressionBuilder::buildOrdering($orderby);
diff --git a/interface.php b/interface.php
index 5572be7..1d8e3ac 100644
--- a/interface.php
+++ b/interface.php
@@ -481,12 +481,35 @@ function get_results_by_gameid(ReqHandler &$rh, array $params): array
     $gameid = trim($params["gameid"]);
     $filter = trim($params["filter"] ?? "");
     $ordering = trim($params["orderby"] ?? "");
+    $groups = explode_list(trim($params["groups"] ?? ""));
 
     $game = $gameMgr->getGame($gameid);
 
     $result = [];
     if (($game !== null) && ($game->isUserContributorOrOwner($user->getNickname()) || $user->hasQuizmasterPrivilege())) {
-        $game_results = $testMgr->getResultsByGameId($gameid, $filter, $ordering, true);
+        $group_filter = [];
+        if ($groups !== []) {
+            global $groupMgr;
+            $n = 0;
+            foreach ($groups as $groupname) {
+                if ($n > 0) { // place OR between each group criterion
+                    $group_filter[] = "OR";
+                }
+                $group = $groupMgr->getGroupByUniqueName($groupname);
+                if ($group !== null) {
+                    $nicknames = $group->getMembers();
+                    $group_filter[] = ["nickname", "IN", $nicknames];
+                }
+                $n++;
+            }
+
+            // prepend filter criteria with AND
+//            if (count($group_filter) > 0) {
+//                $group_filter = ["AND", $group_filter];
+//            }
+        }
+
+        $game_results = $testMgr->getResultsByGameId($gameid, $filter, $ordering, true, $group_filter);
         $result = $game_results;
     }
 
diff --git a/js/result_analyzer.js b/js/result_analyzer.js
index fec5b8c..513b7ff 100644
--- a/js/result_analyzer.js
+++ b/js/result_analyzer.js
@@ -35,6 +35,7 @@ function fetch_results() {
 
     let filterF = document.getElementById("filter");
     let orderbyF = document.getElementById("orderby");
+    let groupsF = document.getElementById("groups");
 
     let filter = autoconvert_datetime(filterF.value.trim());
 
@@ -44,7 +45,8 @@ function fetch_results() {
         action: "get_results_by_gameid",
         gameid: GAMEID,
         filter: filter.trim(),
-        orderby: orderbyF.value.trim()
+        orderby: orderbyF.value.trim(),
+        groups: groupsF.value.trim()
     };
 
     request(req).then(resp => {
diff --git a/result_analyzer.php b/result_analyzer.php
index 0fb71e3..d0b208c 100644
--- a/result_analyzer.php
+++ b/result_analyzer.php
@@ -48,7 +48,8 @@ if (!$gameMgr->getGame($game_id)->isUserContributorOrOwner($user_data["nickname"
 
 <section style="margin-bottom: 0.3em">
     <input type="text" placeholder="Szűrőfeltétel" id="filter" style="font-family: 'Monaco', monospace; width: 50em;">
-    <input type="text" placeholder="Rendezés" id="orderby" style="font-family: 'Monaco', monospace; width: 50em;">
+    <input type="text" placeholder="Csoportok" id="groups" style="font-family: 'Monaco', monospace; width: 30em;">
+    <input type="text" placeholder="Rendezés" id="orderby" style="font-family: 'Monaco', monospace; width: 30em;">
     <input type="button" value="Szűrés" onclick="fetch_results()">
     <input type="button" value="Jelentés előállítása" onclick="generate_report()">
     <input type="button" value="Kijelöltek törlése" onclick="delete_tests()">