Add groupby template variables options (#30834)

* Add groupby template variables options

* Apply suggestions from code review

Co-authored-by: Rosa Trieu <[email protected]>

* Apply suggestions from code review

---------

Co-authored-by: Rosa Trieu <[email protected]>

Author: estherk15

content/en/dashboards/template_variables.md

@@ -27,7 +27,7 @@ further_reading:
 
 ## Overview
 
-Template variables allow you to dynamically filter one or more widgets in a dashboard. You can build saved views from your template variable selections to organize and navigate your visualizations through the dropdown selections. 
+Template variables allow you to dynamically filter or group widgets in a dashboard. You can build saved views from your template variable selections to organize and navigate your visualizations through the dropdown selections.
 
 A template variable is defined by:
 
@@ -41,20 +41,28 @@ A template variable is defined by:
 **Note**: If you do not see the tag or attribute you're looking for, it may be because that data hasn't been reported to Datadog recently. For more information, see [Historical Data][4].
 
 ## Add a template variable
+If template variables are already defined, see [Edit a template variable](#edit-a-template-variable). If your dashboard does not have any template variables, you can click the question mark icon to open a help modal on how to use Dashboard Variables.
+
+{{< img src="/dashboards/template_variables/template_variable_menu.png" alt="Template variable menu showing the Configure Dropdown Values option" style="width:80%;" >}}
 
 To add a template variable in a dashboard:
-1. Click **Add Variables**. 
-1. If template variables are already defined, hover over the dashboard header and click the **Edit** button to enter edit mode.
-1. In edit mode, click the **+ (plus)** icon to create a new template variable.
+1. Click **Add Variable**.
+1. You can add both **Filter** and **Group by** variable types.
+   1. Filter: Add a tag or attribute to filter dashboard queries and visualizations.
+   1. Group by: Add a tag or attribute to show a breakdown of groups within your data.
 1. (Optional) After selecting a tag, click the **+ Configure Dropdown Values** button to rename the variable and set default or available values.
-  {{< img src="dashboards/template_variables/add_template_variable_configure_dropdown_values.png" alt="Add Variable popover showing the Configure Dropdown Values button" style="width:80%;" >}}
+1. Click **Save**.
+1. To add more template variables, see [Edit a template variable](#edit-a-template-variable)
+
 
 ## Edit a template variable
 
-To edit a template variable in a dashboard:
-1. Click the **Edit** button in the dashboard header.
+To edit a template variable or add variables:
+1. Hover over the dashboard header and click the **Edit** button.
 1. In edit mode, click on a template variable and make changes in the popover.
 1. To rearrange variables in the header, hover over a variable, then click and drag the drag icon handle.
+1. Click the **+ (plus)** icon to add a new template variable.
+1. (Optional) After selecting a tag, click the **+ Configure Dropdown Values** button to rename the variable and set default or available values.
   {{< img src="dashboards/template_variables/edit_template_variable_drag.png" alt="Template variable edit mode popover showing the drag icon allowing you to rearrange the order" style="width:100%;" >}}
 
 ## Apply a template variable to widgets
@@ -75,31 +83,31 @@ To add a template variable to widget queries:
 ### Create
 
 1. Click on the **Saved Views** dropdown menu to the left of the template variables in your dashboard. When you update a template variable value, the value does not automatically save to a view.
-1. To save your current template variables' values in a view, select **Save selections as view** from the **Saved Views** dropdown menu. 
+1. To save your current template variables' values in a view, select **Save selections as view** from the **Saved Views** dropdown menu.
 1. Enter a unique name for the view with an optional description.
-1. Click **Save**. 
+1. Click **Save**.
 
 {{< img src="/dashboards/template_variables/saved_view_create.png" alt="Create saved views by selecting save selections as view" style="width:100%;" >}}
 
 Your saved view appears in the dropdown menu. Click on the view to retrieve your previously saved template variable values.
 
 ### Delete
 
-1. Click on the saved views dropdown menu and hover over the desired saved view. 
+1. Click on the saved views dropdown menu and hover over the desired saved view.
 1. Click **Delete View**.
 
 ### Modify
 
 The **Default view** can only be edited by changing the default values of the template variables. To edit the Default View:
 1. Hover over the templates.
-1. Click **Edit** when the button appears. 
+1. Click **Edit** when the button appears.
 1. Click **Done** to save.
 
 To modify template variables values for other saved views:
 1. Select the desired saved view from the dropdown menu.
 1. Edit the template variables to have the new desired models.
 1. Open the dropdown menu again.
-1. Click **Save Changes**. 
+1. Click **Save Changes**.
 
 {{< img src="/dashboards/template_variables/saved_views_update_template_variable.png" alt="Modify the template variables of your saved views" style="width:100%;" >}}
 
@@ -111,7 +119,7 @@ To edit the title and description:
 
 ## Usage
 
-Template variables are used in widgets and event overlays. 
+Template variables are used in widgets and event overlays.
 
 ### Logs, APM, and RUM queries
 
@@ -123,7 +131,7 @@ On log, APM, and RUM widgets, you can use wildcards in the middle of a value (fo
 
 ### Widgets
 
-When creating or editing a widget, existing template variables display as options in the `from` field. For example, if you configure the `environment` template variable, the `$environment` option is available as a dynamic variable in the widget. 
+When creating or editing a widget, existing filter template variables display as options in the `from` field, and existing group by template variables display as options following the `by` field. For example, if you configure the `environment` template variable, the `$environment` option is available as a dynamic variable in the widget.
 
 {{< img src="dashboards/template_variables/dynamic_template_variable.png" alt="Template variable can be set dynamically in widgets" style="width:100%;">}}