//Rename your Custom Field...
//Replace Your Custom Field with "custom_eobi_salary"
//Replace Custom Field wiht "custom_percentage_of_employeer_contribution"
//Replace Custom Field wiht "calculate_eobi_5_pct_by_employer"

frappe.ui.form.on('Employee', {
    custom_eobi_salary: function(frm) {
        calculate_eobi_5_pct_by_employer(frm);
    },
    custom_percentage_of_employeer_contribution: function(frm) {
        calculate_eobi_5_pct_by_employer(frm);
    }
});

function calculate_eobi_5_pct_by_employer(frm) {
    var eobi_salary = frm.doc.custom_eobi_salary;
    var employeer_contribution_percentage = frm.doc.custom_percentage_of_employeer_contribution;
    
    if (eobi_salary && employeer_contribution_percentage) {
        var eobi_5_pct_by_employer = (eobi_salary * (employeer_contribution_percentage / 100)).toFixed(2);
        frm.set_value('custom_eobi_5_pct_by_employer', eobi_5_pct_by_employer);
    }
}