Is it possible to add a custom group to an existing tab?

[DerekSalinas]

I have created a custom addin that I would like to house in a custom group the "esri_mapping_homeTab" to the right of the "Offline" group. 

I know i need to be able to update the "esri_mapping" module, but do I need to have the module added first? 

Thanks any help you can provide!

-Derek Salinas

[Wolf]

If this is what you want to implement:

You can model your add-in's config.daml after this:

<modules>
  <insertModule id="GroupInsertTest_Module" className="Module1" autoLoad="false" caption="Module1">
    <groups>
      <group id="GroupInsertTest_Group1" caption="Group 1" appearsOnAddInTab="true">
        <button refID="GroupInsertTest_Button1" size="large" />
        <button refID="GroupInsertTest_Button2" size="large" />
      </group>
    </groups>
    <controls>
      <!-- add your controls here -->
      <button id="GroupInsertTest_Button1" caption="Button 1" className="Button1" loadOnClick="true" smallImage="pack://application:,,,/ArcGIS.Desktop.Resources;component/Images/GenericButtonBlue16.png" largeImage="pack://application:,,,/ArcGIS.Desktop.Resources;component/Images/GenericButtonBlue32.png">
        <tooltip heading="Tooltip Heading">Tooltip text<disabledText /></tooltip>
      </button>
      <button id="GroupInsertTest_Button2" caption="Button 2" className="Button2" loadOnClick="true" smallImage="pack://application:,,,/ArcGIS.Desktop.Resources;component/Images/GenericButtonBlue16.png" largeImage="pack://application:,,,/ArcGIS.Desktop.Resources;component/Images/GenericButtonBlue32.png">
        <tooltip heading="Tooltip Heading">Tooltip text<disabledText /></tooltip>
      </button>
    </controls>
  </insertModule>
	<!--Modifying Core Map Tab-->
	<updateModule refID="esri_mapping">
		<tabs>
			<updateTab refID="esri_mapping_homeTab" >
				<insertGroup refID="GroupInsertTest_Group1" placeWith="esri_mapping_offlineGroup" insert="after" />
			</updateTab>
		</tabs>
	</updateModule>
</modules>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

There's also a sample that adds a button to the "esri mapping homeTab" 
arcgis-pro-sdk-community-samples/Framework/WorkingWithDAML at master · Esri/arcgis-pro-sdk-community...