Custom button field to link to different doctype

I have created a custom doctype to collect additional information of the employee. I need to link that doctype to the Employee using the Custom button field. Could somebody help me on this.

You need to add a custom “Link” field.

currently that is what I have done now. But since the link field has a list view there is a chance of selecting the wrong employee.
how can we use the button to link instead of link filed?

Add a validation, or set filters on the query

I am a beginner to ERPNEXT. Could you please explain how to proceed with (or with some example).

We can help you if you are stuck, maybe you should hire a freelancer. Or maybe someone else on the forum can help you.