$field = TextField::create('Title', 'Title'); $fields->addFieldToTab('Root.Main', $field); $tab = Tab::create('Settings'); $fields->addFieldToTab('Root', $tab); $field = CheckboxField::create('Enabled', 'Enable feature'); $tab->addField($field); $tabName = 'Root.Content.Images'; $before = 'Main'; $field = UploadField::create('Image', 'Image'); $fields->addFieldToTab($tabName, $field, $before);In these examples, we are adding fields to different tabs within a `FieldList`. The first example adds a `TextField` to the `Main` tab, while the second example adds a new `Tab` called `Settings` to the `Root` tab, and then adds a `CheckboxField` to the `Settings` tab. The third example adds an `UploadField` to the `Images` tab, before the `Main` field. This is accomplished by passing the `$before` argument as `Main`. These examples are likely using the SilverStripe framework or a related package.