diff --git a/src/IntervalFilterAllWithTags.cpp b/src/IntervalFilterAllWithTags.cpp
index 19621d8f..89a77de0 100644
--- a/src/IntervalFilterAllWithTags.cpp
+++ b/src/IntervalFilterAllWithTags.cpp
@@ -27,18 +27,59 @@
 #include <IntervalFilterAllWithTags.h>
 #include <Interval.h>
 
-IntervalFilterAllWithTags::IntervalFilterAllWithTags (std::set <std::string> tags): _tags (std::move(tags))
+IntervalFilterAllWithTags::IntervalFilterAllWithTags (std::set <std::string> tags, const bool complexFiltering): _tags (std::move(tags)), _complexFiltering (complexFiltering)
 {}
 
 bool IntervalFilterAllWithTags::accepts (const Interval& interval)
 {
-  for (auto& tag : _tags)
-  {
-    if (! interval.hasTag (tag))
+  if (_complexFiltering) {
+    // TODO: WIP, This does not fully implement boolean logic.
+    // Check if OR exists.
+    bool isOr = false;
+    for (auto& tag : _tags)
     {
-      return false;
+      if (tag == "OR")
+      {
+        isOr = true;
+        break;
+      }
     }
+
+    for (auto& tag : _tags)
+    {
+      // Process negation
+      bool isNegative = tag[0] == '-';
+      std::string tagName = isNegative ? tag.substr(1) : tag;
+      bool hasTag = interval.hasTag(tagName);
+      if (isNegative) hasTag = !hasTag;
+
+      // Return true at the first sign of a tag, if we're using OR logic.
+      if (isOr && hasTag)
+      {
+        return true;
+      }
+
+      // Return false at the first sign of miss, if we're using AND logic.
+      if (!isOr && !hasTag)
+      {
+        return false;
+      }
+    }
+
+    // OR logic : Nothing triggered the match, so this interval does not match.
+    // AND logic: Nothing triggered the miss, so this interval matches.
+    return isOr ? false : true;
   }
+  else {
+    // Old filtering AND logic
+    for (auto& tag : _tags)
+    {
+      if (! interval.hasTag (tag))
+      {
+        return false;
+      }
+    }
 
-  return true;
+    return true;
+  }
 }
diff --git a/src/IntervalFilterAllWithTags.h b/src/IntervalFilterAllWithTags.h
index 9e204113..8418dd30 100644
--- a/src/IntervalFilterAllWithTags.h
+++ b/src/IntervalFilterAllWithTags.h
@@ -35,12 +35,13 @@
 class IntervalFilterAllWithTags : public IntervalFilter
 {
 public:
-  explicit IntervalFilterAllWithTags(std::set <std::string>);
+  explicit IntervalFilterAllWithTags(std::set <std::string>, const bool complexFiltering);
 
   bool accepts (const Interval&) final;
 
 private:
   const std::set <std::string> _tags {};
+  const bool _complexFiltering {};
 };
 
 #endif //INCLUDED_INTERVALFILTERTAGSET
diff --git a/src/commands/CmdChart.cpp b/src/commands/CmdChart.cpp
index 2fcc7f6f..cf322122 100644
--- a/src/commands/CmdChart.cpp
+++ b/src/commands/CmdChart.cpp
@@ -100,7 +100,7 @@ int renderChart (
   // Load the data.
   auto filtering = IntervalFilterAndGroup ({
     new IntervalFilterAllInRange ({ filter.start, filter.end }),
-    new IntervalFilterAllWithTags (filter.tags())
+    new IntervalFilterAllWithTags (filter.tags(), rules.getBoolean("complexFiltering"))
   });
 
   auto tracked = getTracked (database, rules, filtering);
diff --git a/src/commands/CmdContinue.cpp b/src/commands/CmdContinue.cpp
index ba8dac52..5836a8b5 100644
--- a/src/commands/CmdContinue.cpp
+++ b/src/commands/CmdContinue.cpp
@@ -77,7 +77,7 @@ int CmdContinue (
   }
   else if (!filter.tags ().empty ())
   {
-    auto filtering = IntervalFilterAllWithTags (filter.tags());
+    auto filtering = IntervalFilterAllWithTags (filter.tags(), rules.getBoolean("complexFiltering"));
     auto tracked = getTracked (database, rules, filtering);
 
     if (tracked.empty())
diff --git a/src/commands/CmdExport.cpp b/src/commands/CmdExport.cpp
index b1e3d088..e702bd18 100644
--- a/src/commands/CmdExport.cpp
+++ b/src/commands/CmdExport.cpp
@@ -41,7 +41,7 @@ int CmdExport (
 
   auto filtering = IntervalFilterAndGroup ({
     new IntervalFilterAllInRange ({ filter.start, filter.end }),
-    new IntervalFilterAllWithTags (filter.tags())
+    new IntervalFilterAllWithTags (filter.tags(), rules.getBoolean("complexFiltering"))
   });
 
   auto tracked = getTracked (database, rules, filtering);
diff --git a/src/commands/CmdReport.cpp b/src/commands/CmdReport.cpp
index 7f811024..d16a9218 100644
--- a/src/commands/CmdReport.cpp
+++ b/src/commands/CmdReport.cpp
@@ -96,7 +96,7 @@ int CmdReport (
   auto filter = cli.getFilter ();
   auto filtering = IntervalFilterAndGroup ({
     new IntervalFilterAllInRange ({ filter.start, filter.end }),
-    new IntervalFilterAllWithTags (filter.tags ())
+    new IntervalFilterAllWithTags (filter.tags(), rules.getBoolean("complexFiltering"))
   });
 
   auto tracked = getTracked (database, rules, filtering);
diff --git a/src/commands/CmdSummary.cpp b/src/commands/CmdSummary.cpp
index 6f795b0a..e5e6de0a 100644
--- a/src/commands/CmdSummary.cpp
+++ b/src/commands/CmdSummary.cpp
@@ -53,7 +53,7 @@ int CmdSummary (
   // Load the data.
   auto filtering = IntervalFilterAndGroup ({
     new IntervalFilterAllInRange ({ filter.start, filter.end }),
-    new IntervalFilterAllWithTags (filter.tags())
+    new IntervalFilterAllWithTags (filter.tags(), rules.getBoolean("complexFiltering"))
   });
 
   auto tracked = getTracked (database, rules, filtering);
diff --git a/src/commands/CmdTags.cpp b/src/commands/CmdTags.cpp
index 47d45b99..c7536ec3 100644
--- a/src/commands/CmdTags.cpp
+++ b/src/commands/CmdTags.cpp
@@ -47,7 +47,7 @@ int CmdTags (
   auto filter = cli.getFilter ();
   auto filtering = IntervalFilterAndGroup ({
     new IntervalFilterAllInRange ({ filter.start, filter.end }),
-    new IntervalFilterAllWithTags (filter.tags ())
+    new IntervalFilterAllWithTags (filter.tags(), rules.getBoolean("complexFiltering"))
   });
 
   // Generate a unique, ordered list of tags.
diff --git a/src/dom.cpp b/src/dom.cpp
index 689971a3..a6bd58f3 100644
--- a/src/dom.cpp
+++ b/src/dom.cpp
@@ -112,7 +112,7 @@ bool domGet (
     {
       auto filtering = IntervalFilterAndGroup ({
         new IntervalFilterAllInRange ({ filter.start, filter.end }),
-        new IntervalFilterAllWithTags (filter.tags())
+        new IntervalFilterAllWithTags (filter.tags(), rules.getBoolean("complexFiltering"))
       });
 
       auto tracked = getTracked (database, rules, filtering);