Pre Validation on Submit button IN ICP

Summary:

How to validate based on business reequipment on submit button.

Content (required):

We have a requirement to validate ICP plan while at the time of Submitting. For Example, we have a Allowance which based on Input values which mean element should not be allowed with element name with same input values, so how can we validate this.

Version (include the version you are using, if applicable):

21D

Code Snippet (add any code snippets that support your topic, if applicable):