The PlayScore 2 Documents screen shows all your playable scores as thumbnails of the music, displayed sorted and searchable by Title and Composer.
To make it easier to search and sort, use both the Title and Composer fields.  You can set these from the Play screen.  To see the Composer field, pull down the slider under the Title, or tap the cogwheel .
In the Documents screen you can keep your documents sorted by Title, by Composer or by recency.  To display only matching documents, type in the search box.
PlayScore 2 does not sync the documents screen between devices, but you can archive to bulk to storage (eg iCloud).  From the Documents screen tap Select.  Now tap all the documents you want to copy and tap the export icon.  This action does not remove the documents from the Documents screen.  Documents can be deleted separately by selecting and tapping the trash .