Add the following code under <menulist displayname="System Operations" basename="System Operations" class="security" id="sysopmenu">
<menuitem class="security" id="exportmenu2">
<displayname>Export Metadata (File)</displayname>
<url>CopyMetaData?&action=export</url>
</menuitem>
</menulist>
After adding the code it should look like the following.
<menulist displayname="System Operations" basename="System Operations" class="security" id="sysopmenu">
<menuitem class="security" id="importmenu">
<displayname>Import Metadata</displayname>
<url>CopyMetaData?&action=import</url>
</menuitem>
<menuitem class="security" id="exportmenu">
<displayname>Export Metadata</displayname>
<url>ExportMetadata?&action=list</url>
</menuitem>
<menuitem class="security" id="exportmenu2">
<displayname>Export Metadata (File)</displayname>
<url>CopyMetaData?&action=export</url>
</menuitem>
</menulist>
If "config/security/allmenu.xml=true" is in migrateConfigFolderFiles.prop, then it will replace Allmenu.xml from MDM 8.2.1 file to 8.3.2 during migration. If there are no changes in 8.2.1, then we need to insert "config/security/allmenu.xml=false" and run it.