Finder of Paths Unseen has three Unique Powers which move/push pieces to "a land". Does that have to be a single land for the whole Power use?

Finder of Paths Unseen has three Unique Powers which move/push pieces to "a land". Does that have to be a single land for the whole Power use?

Yes – if you could move/push them freely it would say "to lands" or "to one or more lands" instead of "to a land".
By contrast, Traveler's Boon can move pieces from different lands – though they have to all end up in the same place.