diff --git a/lib/miq_expression.rb b/lib/miq_expression.rb
index 4a19cee8100..8f7ca68d226 100644
--- a/lib/miq_expression.rb
+++ b/lib/miq_expression.rb
@@ -43,6 +43,16 @@ def valid?(component = exp)
     end
   end
 
+  def set_tagged_target(model, associations = [])
+    each_atom(exp) do |atom|
+      next unless atom.key?("tag")
+      tag = Tag.parse(atom["tag"])
+      tag.model = model
+      tag.associations = associations
+      atom["tag"] = tag.to_s
+    end
+  end
+
   def self.proto?
     return @proto if defined?(@proto)
     @proto = ::Settings.product.proto
@@ -1436,4 +1446,19 @@ def self.determine_relat_path(ref)
     last_path
   end
   private_class_method :determine_relat_path
+
+  def each_atom(component, &block)
+    operator = component.keys.first
+
+    case operator.downcase
+    when "and", "or"
+      component[operator].each { |sub_component| each_atom(sub_component, &block) }
+    when "not", "!"
+      each_atom(component[operator], &block)
+    when "find"
+      component[operator].each { |_operator, operands| each_atom(operands, &block) }
+    else
+      yield(component[operator])
+    end
+  end
 end # class MiqExpression
diff --git a/lib/miq_expression/field.rb b/lib/miq_expression/field.rb
index 81bd4336720..6745f29c6e5 100644
--- a/lib/miq_expression/field.rb
+++ b/lib/miq_expression/field.rb
@@ -12,6 +12,7 @@ class MiqExpression::Field < MiqExpression::Target
 
   def self.parse(field)
     parsed_params = parse_params(field) || return
+    return unless parsed_params[:model_name]
     new(parsed_params[:model_name], parsed_params[:associations], parsed_params[:column] ||
         parsed_params[:virtual_custom_column])
   end
diff --git a/lib/miq_expression/tag.rb b/lib/miq_expression/tag.rb
index 161483108ce..758d1862c8a 100644
--- a/lib/miq_expression/tag.rb
+++ b/lib/miq_expression/tag.rb
@@ -1,7 +1,7 @@
 class MiqExpression::Tag < MiqExpression::Target
   REGEX = /
-(?<model_name>([[:alnum:]]*(::)?)+)
-\.(?<associations>([a-z_]+\.)*)
+(?<model_name>([[:alnum:]]*(::)?)?)
+\.?(?<associations>([a-z_]+\.)*)
 (?<namespace>\bmanaged|user_tag\b)
 -(?<column>[a-z]+[_[:alnum:]]+)
 /x
diff --git a/lib/miq_expression/target.rb b/lib/miq_expression/target.rb
index 77a2f24a413..557f915a227 100644
--- a/lib/miq_expression/target.rb
+++ b/lib/miq_expression/target.rb
@@ -13,12 +13,13 @@ def self.parse_params(field)
     # convert matches to hash to format
     # {:model_name => 'User', :associations => ...}
     parsed_params = Hash[match.names.map(&:to_sym).zip(match.to_a[1..-1])]
-    parsed_params[:model_name] = parsed_params[:model_name].classify.safe_constantize || return
+    parsed_params[:model_name] = parsed_params[:model_name].classify.safe_constantize
     parsed_params[:associations] = parsed_params[:associations].to_s.split(".")
     parsed_params
   end
 
-  attr_reader :model, :associations, :column
+  attr_reader :column
+  attr_accessor :model, :associations
 
   def initialize(model, associations, column)
     @model = model
diff --git a/spec/lib/miq_expression/tag_spec.rb b/spec/lib/miq_expression/tag_spec.rb
index 860b998e2bc..2529c3a041a 100644
--- a/spec/lib/miq_expression/tag_spec.rb
+++ b/spec/lib/miq_expression/tag_spec.rb
@@ -47,9 +47,11 @@
       expect(described_class.parse(tag)).to be_nil
     end
 
-    it "returns nil with invalid case managed-tag" do
+    it "supports managed-tag (no model)" do
       tag = "managed-service_level"
-      expect(described_class.parse(tag)).to be_nil
+      expect(described_class.parse(tag)).to have_attributes(:model        => nil,
+                                                            :associations => [],
+                                                            :namespace    => "/managed/service_level")
     end
 
     it "returns nil with invalid case managed" do
diff --git a/spec/lib/miq_expression_spec.rb b/spec/lib/miq_expression_spec.rb
index f46b37693fb..fb357e11b46 100644
--- a/spec/lib/miq_expression_spec.rb
+++ b/spec/lib/miq_expression_spec.rb
@@ -3152,4 +3152,85 @@
       )
     end
   end
+
+  describe "#set_tagged_target" do
+    it "will substitute a new class into the expression" do
+      expression = described_class.new("CONTAINS" => {"tag" => "managed-environment", "value" => "prod"})
+
+      expression.set_tagged_target(Vm)
+
+      expect(expression.exp).to eq("CONTAINS" => {"tag" => "Vm.managed-environment", "value" => "prod"})
+    end
+
+    it "will substitute a new class and associations into the expression" do
+      expression = described_class.new("CONTAINS" => {"tag" => "managed-environment", "value" => "prod"})
+
+      expression.set_tagged_target(Vm, ["host"])
+
+      expect(expression.exp).to eq("CONTAINS" => {"tag" => "Vm.host.managed-environment", "value" => "prod"})
+    end
+
+    it "can handle OR expressions" do
+      expression = described_class.new(
+        "OR" => [
+          {"CONTAINS" => {"tag" => "managed-environment", "value" => "prod"}},
+          {"CONTAINS" => {"tag" => "managed-location", "value" => "ny"}}
+        ]
+      )
+
+      expression.set_tagged_target(Vm)
+
+      expected = {
+        "OR" => [
+          {"CONTAINS" => {"tag" => "Vm.managed-environment", "value" => "prod"}},
+          {"CONTAINS" => {"tag" => "Vm.managed-location", "value" => "ny"}}
+        ]
+      }
+      expect(expression.exp).to eq(expected)
+    end
+
+    it "can handle AND expressions" do
+      expression = described_class.new(
+        "AND" => [
+          {"CONTAINS" => {"tag" => "managed-environment", "value" => "prod"}},
+          {"CONTAINS" => {"tag" => "managed-location", "value" => "ny"}}
+        ]
+      )
+
+      expression.set_tagged_target(Vm)
+
+      expected = {
+        "AND" => [
+          {"CONTAINS" => {"tag" => "Vm.managed-environment", "value" => "prod"}},
+          {"CONTAINS" => {"tag" => "Vm.managed-location", "value" => "ny"}}
+        ]
+      }
+      expect(expression.exp).to eq(expected)
+    end
+
+    it "can handle NOT expressions" do
+      expression = described_class.new("NOT" => {"CONTAINS" => {"tag" => "managed-environment", "value" => "prod"}})
+
+      expression.set_tagged_target(Vm)
+
+      expected = {"NOT" => {"CONTAINS" => {"tag" => "Vm.managed-environment", "value" => "prod"}}}
+      expect(expression.exp).to eq(expected)
+    end
+
+    it "will not change the target of fields" do
+      expression = described_class.new("=" => {"field" => "Vm-vendor", "value" => "redhat"})
+
+      expression.set_tagged_target(Host)
+
+      expect(expression.exp).to eq("=" => {"field" => "Vm-vendor", "value" => "redhat"})
+    end
+
+    it "will not change the target of counts" do
+      expression = described_class.new("=" => {"count" => "Vm.disks", "value" => "1"})
+
+      expression.set_tagged_target(Host)
+
+      expect(expression.exp).to eq("=" => {"count" => "Vm.disks", "value" => "1"})
+    end
+  end
 end