Sick dogwood tree
Your dogwood, or Cornus, tree does seem to have a problem more than under watering or common leaf scorch. I can’t offer a diagnosis based on these photos. You may want to hire an arborist to make a site visit if this is a high-value tree in your landscape. For us to trouble shoot it with you more, look for cankers in the bark, usually below these troubled leaf areas (or the trunk, if whole tree is involved). What might cankers look like? Do an internet search ‘cornus canker’, select images. This can give you an idea of how bark cankers may appear. Send photos of what you find.