I wrote a blog a few months ago titled How to Conditionally Require Data in SharePoint Columns. Since then, I’ve had several readers ask if it was possible to use list validation to conditionally require data in more than one SharePoint column. So, I decided, why not write a Part 2 to that blog to detail how to accomplish this.
For anyone that has not read the first blog, the purpose of list validation is to ensure that the user has entered all required data, or that the data they have entered is valid. This blog will explain the nested IF statement and demonstrate how to use it for multiple column validation.
List Validation settings can be located in List Settings, then Validation settings under the General Settings heading: