docs: clarify Transfer filterOption description (#39916)

close #39907
close #39906

components/transfer/index.en-US.md

@@ -36,7 +36,7 @@ One or more elements can be selected from either column, one click on the proper
 | --- | --- | --- | --- | --- |
 | dataSource | Used for setting the source data. The elements that are part of this array will be present the left column. Except the elements whose keys are included in `targetKeys` prop | [RecordType extends TransferItem = TransferItem](https://github.com/ant-design/ant-design/blob/1bf0bab2a7bc0a774119f501806e3e0e3a6ba283/components/transfer/index.tsx#L12)\[] | \[] |  |
 | disabled | Whether disabled transfer | boolean | false |  |
-| filterOption | A function to determine whether an item should show in search result list | (inputValue, option): boolean | - |  |
+| filterOption | A function to determine whether an item should show in search result list, only works when searching | (inputValue, option): boolean | - |  |
 | footer | A function used for rendering the footer | (props, { direction }) => ReactNode | - | direction: 4.17.0 |
 | listStyle | A custom CSS style used for rendering the transfer columns | object \| ({direction: `left` \| `right`}) => object | - |  |
 | locale | The i18n text including filter, empty text, item unit, etc | { itemUnit: string; itemsUnit: string; searchPlaceholder: string; notFoundContent: ReactNode \| ReactNode[]; } | { itemUnit: `item`, itemsUnit: `items`, notFoundContent: `The list is empty`, searchPlaceholder: `Search here` } |  |

components/transfer/index.zh-CN.md

@@ -39,7 +39,7 @@ cover: https://mdn.alipayobjects.com/huamei_7uahnr/afts/img/A*EAApQ5ephigAAAAAAA
 | --- | --- | --- | --- | --- |
 | dataSource | 数据源，其中的数据将会被渲染到左边一栏中，`targetKeys` 中指定的除外 | [RecordType extends TransferItem = TransferItem](https://github.com/ant-design/ant-design/blob/1bf0bab2a7bc0a774119f501806e3e0e3a6ba283/components/transfer/index.tsx#L12)\[] | \[] |  |
 | disabled | 是否禁用 | boolean | false |  |
-| filterOption | 接收 `inputValue` `option` 两个参数，当 `option` 符合筛选条件时，应返回 true，反之则返回 false | (inputValue, option): boolean | - |  |
+| filterOption | 根据搜索内容进行筛选，接收 `inputValue` `option` 两个参数，当 `option` 符合筛选条件时，应返回 true，反之则返回 false | (inputValue, option): boolean | - |  |
 | footer | 底部渲染函数 | (props, { direction }) => ReactNode | - | direction: 4.17.0 |
 | listStyle | 两个穿梭框的自定义样式 | object\|({direction: `left` \| `right`}) => object | - |  |
 | locale | 各种语言 | { itemUnit: string; itemsUnit: string; searchPlaceholder: string; notFoundContent: ReactNode \| ReactNode[]; } | { itemUnit: `项`, itemsUnit: `项`, searchPlaceholder: `请输入搜索内容` } |  |