Bulk Unpin on android

[dragon2611]

I'm probably being really stupid with this one, but how do you bulk unpin on android, ideally i'd like to unpin everything and start again.

Basically I accidentally did a Pin very high up in my folder structure so ended up pinning every song by a perticullar aritst, It seems you can go down through the folders and then bulk select all the titles in a folder and unpin them, but there seems to be no obvious way to do it from the top level tree.