diff --git a/src/Base/Parameter.cpp b/src/Base/Parameter.cpp
index 665a8fcf14..fb09734944 100644
--- a/src/Base/Parameter.cpp
+++ b/src/Base/Parameter.cpp
@@ -2060,16 +2060,15 @@ DOMPrintFilter::FilterAction DOMPrintFilter::acceptNode(const DOMNode* node) con
         }
     }
 
+    // clang-format off
     switch (node->getNodeType()) {
         case DOMNode::TEXT_NODE: {
             // Filter out text element if it is under a group node. Note text xml
             // element is plain text in between tags, and we do not store any text
             // there.
             auto parent = node->getParentNode();
-            if (parent
-                && XMLString::compareString(parent->getNodeName(),
-                                            XStr("FCParamGroup").unicodeForm())
-                    == 0) {
+            if (parent && XMLString::compareString(parent->getNodeName(),
+                                                   XStr("FCParamGroup").unicodeForm()) == 0) {
                 return DOMNodeFilter::FILTER_REJECT;
             }
             return DOMNodeFilter::FILTER_ACCEPT;
@@ -2082,6 +2081,7 @@ DOMPrintFilter::FilterAction DOMPrintFilter::acceptNode(const DOMNode* node) con
             return DOMNodeFilter::FILTER_ACCEPT;
         }
     }
+    // clang-format on
 }
 
 //**************************************************************************
diff --git a/tests/src/Base/Parameter.cpp b/tests/src/Base/Parameter.cpp
index 704ba93e07..a7aad26d20 100644
--- a/tests/src/Base/Parameter.cpp
+++ b/tests/src/Base/Parameter.cpp
@@ -1,6 +1,38 @@
 #include "gtest/gtest.h"
+#include <boost/core/ignore_unused.hpp>
+#include <Base/FileInfo.h>
 #include <Base/Parameter.h>
 
+class FakeObserver: public ParameterGrp::ObserverType
+{
+public:
+    void clearNotifications()
+    {
+        notify = 0;
+    }
+    int getCountNotifications() const
+    {
+        return notify;
+    }
+    void attachSelf(ParameterGrp::handle hGrp)
+    {
+        hGrp->Attach(this);
+    }
+    void detachSelf(ParameterGrp::handle hGrp)
+    {
+        hGrp->Detach(this);
+    }
+    void OnChange(ParameterGrp::SubjectType& rCaller, ParameterGrp::MessageType Reason) override
+    {
+        boost::ignore_unused(rCaller);
+        boost::ignore_unused(Reason);
+        notify++;
+    }
+
+private:
+    int notify {};
+};
+
 class ParameterTest: public ::testing::Test
 {
 protected:
@@ -9,13 +41,22 @@ protected:
         ParameterManager::Init();
     }
 
+    ParameterTest()
+    {
+        fi.setFile(Base::FileInfo::getTempFileName() + ".cfg");
+    }
+
     void SetUp() override
     {
         config = ParameterManager::Create();
     }
 
     void TearDown() override
-    {}
+    {
+        if (fi.exists()) {
+            fi.deleteFile();
+        }
+    }
 
     Base::Reference<ParameterManager> getConfig() const
     {
@@ -28,7 +69,19 @@ protected:
         return config;
     }
 
+    std::string getFileName() const
+    {
+        return fi.filePath();
+    }
+
+    FakeObserver& getObserver()
+    {
+        return observer;
+    }
+
 private:
+    Base::FileInfo fi;
+    FakeObserver observer;
     Base::Reference<ParameterManager> config;
 };
 
@@ -70,6 +123,23 @@ TEST_F(ParameterTest, TestGroupName)
     EXPECT_STREQ(grp->GetGroupName(), "TopLevelGroup");
 }
 
+TEST_F(ParameterTest, TestEmptyGroupName)
+{
+    auto cfg = getCreateConfig();
+    EXPECT_THROW(cfg->GetGroup(nullptr), Base::ValueError);
+    EXPECT_THROW(cfg->GetGroup(""), Base::ValueError);
+    EXPECT_THROW(cfg->GetGroup("///////"), Base::ValueError);
+}
+
+TEST_F(ParameterTest, TestGroupNames)
+{
+    auto cfg = getCreateConfig();
+    auto grp1 = cfg->GetGroup("////Sub1/////Sub2/////");
+    auto grp2 = cfg->GetGroup("Sub1/Sub2");
+    EXPECT_STREQ(grp1->GetGroupName(), "Sub2");
+    EXPECT_STREQ(grp2->GetGroupName(), "Sub2");
+}
+
 TEST_F(ParameterTest, TestPath)
 {
     auto cfg = getCreateConfig();
@@ -257,4 +327,119 @@ TEST_F(ParameterTest, TestRenameGroup)
     cfg->CheckDocument();
 }
 
+TEST_F(ParameterTest, TestSaveRestoreRef)
+{
+    auto cfg = getCreateConfig();
+    auto grp = cfg->GetGroup("TopLevelGroup/Sub1/Sub2");
+    grp->SetFloat("Float", 1.0);
+    cfg->CheckDocument();
+
+    std::string fn = getFileName();
+    cfg->exportTo(fn.c_str());
+
+    cfg->importFrom(fn.c_str());
+    auto grp2 = cfg->GetGroup("TopLevelGroup/Sub1/Sub2");
+    EXPECT_EQ(grp, grp2);
+
+    grp2->SetFloat("Float", 2.0);
+    cfg->exportTo(fn.c_str());
+}
+
+TEST_F(ParameterTest, TestSaveRestoreNoRef)
+{
+    auto cfg = getCreateConfig();
+    auto grp = cfg->GetGroup("TopLevelGroup/Sub1/Sub2");
+    grp->SetFloat("Float", 1.0);
+    grp = nullptr;
+    cfg->CheckDocument();
+
+    std::string fn = getFileName();
+    cfg->exportTo(fn.c_str());
+
+    cfg->importFrom(fn.c_str());
+    auto grp2 = cfg->GetGroup("TopLevelGroup/Sub1/Sub2");
+    EXPECT_NE(grp, grp2);
+
+    grp2->SetFloat("Float", 2.0);
+    cfg->exportTo(fn.c_str());
+}
+
+TEST_F(ParameterTest, TestGroupRef)
+{
+    auto cfg = getCreateConfig();
+    cfg->GetGroup("TopLevelGroup");
+
+    std::string fn = getFileName();
+    cfg->exportTo(fn.c_str());
+
+    // keep reference to prevent the deletion of the group node
+    auto grp = cfg->GetGroup("TopLevelGroup/Sub1/Sub2");
+    cfg->importFrom(fn.c_str());
+    auto top = cfg->GetGroup("TopLevelGroup");
+    EXPECT_TRUE(top->HasGroup("Sub1"));
+}
+
+TEST_F(ParameterTest, TestGroupNoRef)
+{
+    auto cfg = getCreateConfig();
+    cfg->GetGroup("TopLevelGroup");
+
+    std::string fn = getFileName();
+    cfg->exportTo(fn.c_str());
+
+    // nullify reference to delete the group node
+    auto grp = cfg->GetGroup("TopLevelGroup/Sub1/Sub2");
+    grp = nullptr;
+
+    cfg->importFrom(fn.c_str());
+    auto top = cfg->GetGroup("TopLevelGroup");
+    EXPECT_FALSE(top->HasGroup("Sub1"));
+}
+
+TEST_F(ParameterTest, TestObserverRef)
+{
+    auto cfg = getCreateConfig();
+    cfg->GetGroup("TopLevelGroup");
+
+    std::string fn = getFileName();
+    cfg->exportTo(fn.c_str());
+
+    auto grp = cfg->GetGroup("TopLevelGroup/Sub1/Sub2");
+
+    auto& obs = getObserver();
+    obs.attachSelf(grp);
+
+    grp->SetFloat("Float", 1.0);
+
+    EXPECT_EQ(obs.getCountNotifications(), 1);
+    obs.clearNotifications();
+
+    cfg->importFrom(fn.c_str());
+
+    grp->SetFloat("Float", 2.0);
+    EXPECT_EQ(obs.getCountNotifications(), 3);
+    obs.detachSelf(grp);
+}
+
+TEST_F(ParameterTest, TestObserverNoRef)
+{
+    auto cfg = getCreateConfig();
+    cfg->GetGroup("TopLevelGroup");
+
+    std::string fn = getFileName();
+    cfg->exportTo(fn.c_str());
+
+    auto grp = cfg->GetGroup("TopLevelGroup/Sub1/Sub2");
+
+    auto& obs = getObserver();
+    obs.attachSelf(grp);
+    grp = nullptr;
+
+    cfg->importFrom(fn.c_str());
+
+    auto grp2 = cfg->GetGroup("TopLevelGroup/Sub1/Sub2");
+    grp2->SetFloat("Float", 2.0);
+    EXPECT_EQ(obs.getCountNotifications(), 1);
+}
+
 // NOLINTEND(cppcoreguidelines-*,readability-*)