How to add custom button(Multi selection) inside the form

I want to add a multiselection custom button inside the form view like other fields. But the custom button is only placed on the top right where other buttons are.

frm.add_custom_button((‘Verified’), function(){
frappe.msgprint(“Document verified successfully”);
},(“Verification”));

frm.add_custom_button((‘Returned’), function(){
frappe.msgprint(“Document Returned”);
},(“Verification”));
}

This is the result I am getting now,
image (6)

But i want the button to be placed as seen in the reference image below,

Welcome @AswathiKiebot
add custom filed ( select filed )