Add mention about Branch line filter on History Pane

content/en/docs/refguide/modeling/menus/version-control-menu/history-dialog.md

@@ -29,6 +29,22 @@
 * The search bar looks in all fields of the revisions grid and in the details of the commit, such as the Model changes, Disk changes and Stories.
 * The date filter allows specifying a date range for revisions. The available presets help to quickly select a range.
 * The document filter allows selecting a document, such as a specific microflow, to filter all revisions on.
+* The branch line filter limits the history to commits from a selected branch. See [Branch Line Filter](#branch-line-filter) below.
+
+#### Branch Line Filter{#branch-line-filter}
+
+The **Branch Line** ComboBox is always visible in the History pane toolbar. It filters the commit history to show only commits from a selected branch line.
+
+By default, the ComboBox displays the current branch name and no filter is active, so the history shows all commits on the current branch. The current branch is highlighted at the top of the dropdown list; all other branches are listed alphabetically.
+
+To filter by branch:
+
+1. Click or type in the **Select branch line** ComboBox in the toolbar.
+2. Select a branch from the dropdown list, or type to narrow the list.
+3. The history grid filters immediately and a **Clear branch filter** button appears to the right of the ComboBox.
+4. To clear the filter, click **Clear branch filter** — the ComboBox resets to the current branch and the **Clear branch filter** button is hidden.
+
+To reload the branch list without losing your current filter selection, click the **Refresh branch list** button to the right of the ComboBox.
 
 ### Content