diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/tools/viewlog.tt b/koha-tmpl/intranet-tmpl/prog/en/modules/tools/viewlog.tt
index 19b7f7a63f..343706cb2c 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/tools/viewlog.tt
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/tools/viewlog.tt
@@ -351,6 +351,8 @@
             actions: [% To.json(actions || []) | $raw %],
             interfaces: [% To.json(interfaces || []) | $raw %],
             object: "[% object | html %]",
+            object_type: "[% object_type | html %]",
+            biblio_itemnumbers: [% To.json(biblio_itemnumbers || []) | $raw %],
             info: "[% info | html %]",
             datefrom: "[% datefrom | html %]",
             dateto: "[% dateto | html %]",
diff --git a/koha-tmpl/intranet-tmpl/prog/js/viewlog.js b/koha-tmpl/intranet-tmpl/prog/js/viewlog.js
index e7bac21dda..1b11ceedf7 100644
--- a/koha-tmpl/intranet-tmpl/prog/js/viewlog.js
+++ b/koha-tmpl/intranet-tmpl/prog/js/viewlog.js
@@ -419,11 +419,33 @@ function buildApiFilters(params) {
         filters.user = params.user;
     }
 
-    if (params.object) {
+    // Cataloguing modification log: object_type=biblio means we should
+    // surface biblio-level changes ("biblio%") on the biblionumber AND
+    // item-level changes ("item%") on each of the biblio's itemnumbers
+    // (computed server-side and passed in via biblio_itemnumbers).
+    var biblio_expansion = false;
+    if (
+        params.object &&
+        params.object_type === "biblio" &&
+        params.modules &&
+        params.modules.length === 1 &&
+        params.modules[0] === "CATALOGUING"
+    ) {
+        var itemnumbers = params.biblio_itemnumbers || [];
+        var or_clauses = [{ object: params.object, info: { like: "biblio%" } }];
+        if (itemnumbers.length) {
+            or_clauses.push({
+                object: itemnumbers,
+                info: { like: "item%" },
+            });
+        }
+        filters["-or"] = or_clauses;
+        biblio_expansion = true;
+    } else if (params.object) {
         filters.object = params.object;
     }
 
-    if (params.info) {
+    if (params.info && !biblio_expansion) {
         filters.info = { like: "%" + params.info + "%" };
     }
 
diff --git a/tools/viewlog.pl b/tools/viewlog.pl
index 8c711433a5..bb4f8adccf 100755
--- a/tools/viewlog.pl
+++ b/tools/viewlog.pl
@@ -30,6 +30,7 @@ use C4::Serials qw( CountSubscriptionFromBiblionumber );
 use C4::Search  qw( enabled_staff_search_views );
 
 use Koha::ActionLogs;
+use Koha::Biblios;
 use Koha::Database;
 use Koha::DateUtils qw( dt_from_string );
 use Koha::Items;
@@ -91,18 +92,34 @@ $template->param(
 if ($do_it) {
     if ( $output eq "screen" ) {
 
+        # Cataloguing modification log opens with modules=CATALOGUING and
+        # object_type=biblio: surface item-level changes alongside the
+        # biblio ones by collecting the biblio's itemnumbers and asking
+        # the JS to filter on either object set. Mirrors the CSV export
+        # branch below. The biblio object is also exposed so that the
+        # biblio-view-menu sidebar can render its links.
+        my $biblio;
+        my @biblio_itemnumbers;
+        if ( @modules == 1 && $object_type eq 'biblio' && $object ) {
+            $biblio             = Koha::Biblios->find($object);
+            @biblio_itemnumbers = $biblio->items->get_column('itemnumber') if $biblio;
+        }
+
         # Screen output: pass search params to template, DataTable loads via REST API
         $template->param(
-            logview    => 1,
-            do_it      => 1,
-            datefrom   => $datefrom,
-            dateto     => $dateto,
-            user       => $user,
-            info       => $info,
-            src        => $src,
-            modules    => \@modules,
-            actions    => \@actions,
-            interfaces => \@interfaces
+            logview            => 1,
+            do_it              => 1,
+            datefrom           => $datefrom,
+            dateto             => $dateto,
+            user               => $user,
+            info               => $info,
+            src                => $src,
+            modules            => \@modules,
+            actions            => \@actions,
+            interfaces         => \@interfaces,
+            object_type        => $object_type,
+            biblio             => $biblio,
+            biblio_itemnumbers => \@biblio_itemnumbers,
         );
 
         # Used modules