diff --git a/common-lib/common/variables/variables.libsonnet b/common-lib/common/variables/variables.libsonnet
index 951bd94e5..417ae5f9a 100644
--- a/common-lib/common/variables/variables.libsonnet
+++ b/common-lib/common/variables/variables.libsonnet
@@ -13,6 +13,11 @@ local utils = import '../utils.libsonnet';
     prometheusDatasourceName=if enableLokiLogs then 'prometheus_datasource' else 'datasource',
     prometheusDatasourceLabel=if enableLokiLogs then 'Prometheus data source' else 'Data source',
   ): {
+       // strip trailing or starting comma if present:
+       // while trailing comman is accepted in PromQL expressions, starting comma is not.
+       // starting comma can be present in case of concatenation of empty filteringSelector with some extra selectors.
+       local _filteringSelector = std.stripChars(std.stripChars(filteringSelector, ' '), ','),
+
        local varMetricTemplate(varMetric, chainSelector) =
          // check if chainSelector is not empty string (case when filtering selector is empty):
          if std.type(varMetric) == 'array' && chainSelector != ''
@@ -57,16 +62,16 @@ local utils = import '../utils.libsonnet';
        // Use on dashboards where multiple entities can be selected, like fleet dashboards
        multiInstance:
          [root.datasources.prometheus]
-         + variablesFromLabels(groupLabels, instanceLabels, filteringSelector),
+         + variablesFromLabels(groupLabels, instanceLabels, _filteringSelector),
        // Use on dashboards where only single entity can be selected
        singleInstance:
          [root.datasources.prometheus]
-         + variablesFromLabels(groupLabels, instanceLabels, filteringSelector, multiInstance=false),
+         + variablesFromLabels(groupLabels, instanceLabels, _filteringSelector, multiInstance=false),
        queriesSelectorAdvancedSyntax:
          std.join(
            ',',
            std.filter(function(x) std.length(x) > 0, [
-             filteringSelector,
+             _filteringSelector,
              utils.labelsToPromQLSelectorAdvanced(groupLabels + instanceLabels),
            ])
          ),
@@ -74,7 +79,7 @@ local utils = import '../utils.libsonnet';
          std.join(
            ',',
            std.filter(function(x) std.length(x) > 0, [
-             filteringSelector,
+             _filteringSelector,
              utils.labelsToPromQLSelector(groupLabels + instanceLabels),
            ])
          ),
diff --git a/jvm-observ-lib/config.libsonnet b/jvm-observ-lib/config.libsonnet
index c16a36581..5f265a1f1 100644
--- a/jvm-observ-lib/config.libsonnet
+++ b/jvm-observ-lib/config.libsonnet
@@ -1,6 +1,6 @@
 {
   local this = self,
-  filteringSelector: 'job!=""',
+  filteringSelector: '',  // set to apply static filters to all queries and alerts, i.e. job="bar"
   groupLabels: ['job'],
   instanceLabels: ['instance'],
   uid: 'jvm',
diff --git a/kafka-observ-lib/config.libsonnet b/kafka-observ-lib/config.libsonnet
index d6c0e07e1..1b1bbadf0 100644
--- a/kafka-observ-lib/config.libsonnet
+++ b/kafka-observ-lib/config.libsonnet
@@ -1,6 +1,6 @@
 {
   local this = self,
-  filteringSelector: 'job!=""',
+  filteringSelector: '',  // set to apply static filters to all queries and alerts, i.e. job="integrations/kafka"
   zookeeperfilteringSelector: this.filteringSelector,
   groupLabels: ['kafka_cluster'],  // label(s) that defines kafka cluster
   instanceLabels: ['instance'],  // label(s) that defines single broker
diff --git a/process-observ-lib/config.libsonnet b/process-observ-lib/config.libsonnet
index d353e9b55..8e6a08b38 100644
--- a/process-observ-lib/config.libsonnet
+++ b/process-observ-lib/config.libsonnet
@@ -6,7 +6,7 @@
   // 'instanceLabels' - one or more labels that can be used to identify single entity of instances. In simple cases, can be 'instance' or 'pod'.
   // 'uid' - UID to prefix all dashboards original uids
   local this = self,
-  filteringSelector: 'job!=""',
+  filteringSelector: '',  // set to apply static filters to all queries and alerts, i.e. job="bar"
   groupLabels: ['job'],
   instanceLabels: ['instance'],
   dashboardTags: [self.uid],
diff --git a/windows-observ-lib/config.libsonnet b/windows-observ-lib/config.libsonnet
index 8ff0a6e0b..cd603b7ed 100644
--- a/windows-observ-lib/config.libsonnet
+++ b/windows-observ-lib/config.libsonnet
@@ -7,7 +7,7 @@
   // 'uid' - UID to prefix all dashboards original uids
   groupLabels: ['job'],
   instanceLabels: ['instance'],
-  filteringSelector: 'job=~".*windows.*"',
+  filteringSelector: '',  // set to apply static filters to all queries and alerts, i.e. job="windows"
   dashboardTags: ['windows'],
   uid: 'windows',
   dashboardNamePrefix: '',
diff --git a/zookeeper-observ-lib/config.libsonnet b/zookeeper-observ-lib/config.libsonnet
index 0e65a2ca1..7249516dc 100644
--- a/zookeeper-observ-lib/config.libsonnet
+++ b/zookeeper-observ-lib/config.libsonnet
@@ -1,6 +1,6 @@
 {
   local this = self,
-  filteringSelector: 'job!=""',
+  filteringSelector: '',  // set to apply static filters to all queries and alerts, i.e. job="bar"
   groupLabels: ['job'],
   instanceLabels: ['instance'],
   uid: 'zookeeper',