You would set up the field validation by calculation:
Field 2 validation is: If( not IsEmtpy (Field1) ) with a message on validation fail of "Corrective Action must have a Champion" or some such.
If it is certain text you are looking for, it might instead be If(Field1 = "Corrective Action" ; 0 ; 1)
Similar validations would be set for Fields 3&4.
What I would do is launch a script trigger OnModify for Field 1 that pops up a dialog box asking for values of the other fields if Feild1 has a corrective action demand. This would help to avoid the annoying "Validation Fail" error messages.
PS, it's early...I might have the Booleans backwards.
IsEmpty ( Field1 ) or Not IsEmpty (Self )
Is a validation calculation that can be set in field options on fields 2, 3, and 4.
But validation rule violations have just one message that tells the user that something failed a validation. There's no capability to have different messages for each of fields 2, 3, and 4.
To do that, you'd need to write a script and perform that script with the OnObjectValidation trigger.
Thanks to both of you for your responses. I have used PhilModJunk's calculation and the database is now correctly performing the validation query's I required when a corrective action is specified in field 1. ( A person' name, a completion date and a YES/NO option all need to be set)