Just using **iTunes** by itself, I do not know of a way to export multiple **playlists** at the same time, as one can only select one **playlist** in the **Sidebar** at a time.

Normally to export a **playlist** in **iTunes** one would, e.g., select the _target_ **playlist** in the **Sidebar** and then click: **File** > **Library** > **Export Playlist…**

This then brings up a **Save** _dialog box_, e.g.:

[![enter image description here][1]][1]

To semi-automate the process I assigned a _keyboard shortcut_ of **⌘E** to the **Export Playlist…** in **System Preferences** > **Keyboard** > **Shortcuts** > **App Shortcuts**, as shown the image below.

This allows me to easily bring up the **Save** _dialog box_ without having to navigate the _menus_, and I can then just use the _keyboard_ to easily walk through saving one **playlist** after the other.

It's easy to get into a rhythm, select the first **playlist**, then **⌘E** > **enter** > **down-arrow** > **⌘E** > **enter** > **down-arrow** > etc.

[![enter image description here][2]][2]


  [1]: https://i.sstatic.net/aEZBe.png
  [2]: https://i.sstatic.net/YUNxw.png