The druid Círculo del Pastor has the function of the Discourse of the Woods (XGtE, p.23):
You learn to speak, read and write Sylvan. In addition, beasts can understand your speech and you get the ability to decipher their noises and movements.
One of the restrictions of the Wild Shape feature is:
You can not cast spells, and your ability to speak or perform any action that requires hands is limited to the capabilities of your beast form.
Related question: Can a druid speak while in wild form?
Depending on how Speech of the Woods is analyzed, Sylvan can talk and the beasts can understand it when Sylvan speaks (at this point this question is debatable), or Sylvan can speak, and separately, the beasts can understand their speech, probably in any language that you choose
So, if the druid is wild in a wolf, they can only speak "like a wolf" (quite limited). But they can also decipher the sounds and movements of a wolf, and wolves can understand their "speech", however, that is defined.
Am I trying too hard to suggest that the druid can communicate with other beasts when he is in the form of a beast? Or at least other beasts of the same species?