Search your library and graveyard for a card named Forest, a card named Brambleweft Behemoth, and a card named Nissa, Genesis Mage. Reveal those cards, put them into your hand, then shuffle.
Nissa’s Encouragement can’t be used to find a card with the land type Forest that isn’t also named Forest (such as Sheltered Thicket from the Amonkhet set).
You can find any or all of the cards listed with Nissa’s Encouragement. You could even find none, but that wouldn’t be very encouraging.