diff --git a/SabreTools.Core/Filter/FilterGroup.cs b/SabreTools.Core/Filter/FilterGroup.cs
index fa36765d..e5fa844d 100644
--- a/SabreTools.Core/Filter/FilterGroup.cs
+++ b/SabreTools.Core/Filter/FilterGroup.cs
@@ -8,20 +8,20 @@ namespace SabreTools.Core.Filter
     /// </summary>
     public class FilterGroup
     {
+        /// <summary>
+        /// How to apply the group filters
+        /// </summary>
+        public readonly GroupType GroupType;
+
         /// <summary>
         /// All standalone filters in the group
         /// </summary>
-        public readonly List<FilterObject> Subfilters = [];
+        private readonly List<FilterObject> _subfilters = [];
 
         /// <summary>
         /// All filter groups contained in the group
         /// </summary>
-        public readonly List<FilterGroup> Subgroups = [];
-
-        /// <summary>
-        /// How to apply the group filters
-        /// </summary>
-        public readonly GroupType GroupType;
+        private readonly List<FilterGroup> _subgroups = [];
 
         public FilterGroup(GroupType groupType)
         {
@@ -30,23 +30,37 @@ namespace SabreTools.Core.Filter
 
         public FilterGroup(FilterObject[] filters, GroupType groupType)
         {
-            Subfilters.AddRange(filters);
+            _subfilters.AddRange(filters);
             GroupType = groupType;
         }
 
         public FilterGroup(FilterGroup[] groups, GroupType groupType)
         {
-            Subgroups.AddRange(groups);
+            _subgroups.AddRange(groups);
             GroupType = groupType;
         }
 
         public FilterGroup(FilterObject[] filters, FilterGroup[] groups, GroupType groupType)
         {
-            Subfilters.AddRange(filters);
-            Subgroups.AddRange(groups);
+            _subfilters.AddRange(filters);
+            _subgroups.AddRange(groups);
             GroupType = groupType;
         }
 
+        #region Accessors
+
+        /// <summary>
+        /// Add a FilterObject to the set
+        /// </summary>
+        public void AddFilter(FilterObject filter) => _subfilters.Add(filter);
+
+        /// <summary>
+        /// Add a FilterGroup to the set
+        /// </summary>
+        public void AddGroup(FilterGroup group) => _subgroups.Add(group);
+
+        #endregion
+
         #region Matching
 
         /// <summary>
@@ -68,7 +82,7 @@ namespace SabreTools.Core.Filter
         private bool MatchesAnd(DictionaryBase dictionaryBase)
         {
             // Run standalone filters
-            foreach (var filter in Subfilters)
+            foreach (var filter in _subfilters)
             {
                 // One failed match fails the group
                 if (!filter.Matches(dictionaryBase))
@@ -76,7 +90,7 @@ namespace SabreTools.Core.Filter
             }
 
             // Run filter subgroups
-            foreach (var group in Subgroups)
+            foreach (var group in _subgroups)
             {
                 // One failed match fails the group
                 if (!group.Matches(dictionaryBase))
@@ -92,7 +106,7 @@ namespace SabreTools.Core.Filter
         private bool MatchesOr(DictionaryBase dictionaryBase)
         {
             // Run standalone filters
-            foreach (var filter in Subfilters)
+            foreach (var filter in _subfilters)
             {
                 // One successful match passes the group
                 if (filter.Matches(dictionaryBase))
@@ -100,7 +114,7 @@ namespace SabreTools.Core.Filter
             }
 
             // Run filter subgroups
-            foreach (var group in Subgroups)
+            foreach (var group in _subgroups)
             {
                 // One successful match passes the group
                 if (group.Matches(dictionaryBase))
diff --git a/SabreTools.Core/Filter/FilterRunner.cs b/SabreTools.Core/Filter/FilterRunner.cs
index 7410877e..512fd4d3 100644
--- a/SabreTools.Core/Filter/FilterRunner.cs
+++ b/SabreTools.Core/Filter/FilterRunner.cs
@@ -13,7 +13,7 @@ namespace SabreTools.Core.Filter
         /// <summary>
         /// Set of filters to be run against an object
         /// </summary>
-        public readonly Dictionary<string, List<FilterObject>> Filters = [];
+        public readonly Dictionary<string, FilterGroup> Filters = [];
 
         /// <summary>
         /// Cached item type names for filter selection
@@ -23,7 +23,7 @@ namespace SabreTools.Core.Filter
         /// <summary>
         /// Set of machine type keys that are logically grouped
         /// </summary>
-        /// TODO: REMOVE THISWHEN A PROPER IMPLEMENTATION IS FOUND
+        /// TODO: REMOVE THIS WHEN A PROPER IMPLEMENTATION IS FOUND
         private readonly string[] _machineTypeKeys =
         [
             $"{MetadataFile.MachineKey}.{Machine.IsBiosKey}",
@@ -38,10 +38,10 @@ namespace SabreTools.Core.Filter
                 // Ensure the key exists
                 string key = filter.Key.ToString();
                 if (!Filters.ContainsKey(filter.Key.ToString()))
-                    Filters[key] = [];
+                    Filters[key] = new FilterGroup(GroupType.OR);
 
                 // Add the filter to the set
-                Filters[key].Add(filter);
+                Filters[key].AddFilter(filter);
             }
         }
 
@@ -56,10 +56,10 @@ namespace SabreTools.Core.Filter
                     // Ensure the key exists
                     string key = filter.Key.ToString();
                     if (!Filters.ContainsKey(filter.Key.ToString()))
-                        Filters[key] = [];
+                        Filters[key] = new FilterGroup(GroupType.OR);
 
                     // Add the filter to the set
-                    Filters[key].Add(filter);
+                    Filters[key].AddFilter(filter);
                 }
                 catch { }
             }
@@ -104,10 +104,8 @@ namespace SabreTools.Core.Filter
                         if (!Filters.ContainsKey(filterKey))
                             continue;
 
-                        foreach (var filter in Filters[filterKey])
-                        {
-                            matchAny |= filter.Matches(dictionaryBase);
-                        }
+                        // Check for a match like normal
+                        matchAny |= Filters[filterKey].Matches(dictionaryBase);
                     }
 
                     // If we don't get a match, it's a failure
@@ -129,13 +127,8 @@ namespace SabreTools.Core.Filter
                 if (Array.Exists(_machineTypeKeys, key => key == filterKey))
                     continue;
 
-                bool matchOne = false;
-                foreach (var filter in Filters[filterKey])
-                {
-                    matchOne |= filter.Matches(dictionaryBase);
-                }
-
                 // If we don't get a match, it's a failure
+                bool matchOne = Filters[filterKey].Matches(dictionaryBase);
                 if (!matchOne)
                     return false;
             }