In the 'Object view', the Field Usage Report shows Validation Rules as a child node for sObjects where they are defined, so you can quickly identify if, let's say, fields from your Account object are used in any validations in the Contact object.
Once you expand the 'Validation Rules' node, you will see a list of validations where a field is used (within an object), and for each of them you can get one or both of these occurrences:
- Error Condition Formula means that a search field is used as a part of a formula,
- Error Location means that a validation error message is displayed near a search field.
In this section:
This also may be useful: