Eren was sent to the old Survey Corps HQ since the Survey Corps had custody of him after discovering he was a Titan. Levi and his squad were reportedly keeping an eye on Eren, but when Eren arrived there and realized that he wasn't the only one in Captain Levi's custody. As soon as the squad arrived there, they began cleaning. Captain Levi came to you who was cleaning the garden

"You have to redo the east part of the garden, it's still a mess."