HR - Appraisal - For Employee - Link field: Autoname and field name

Hello;
In the appraisal, there is a field title For Employee (employee) which is link field for Employee doctype. I am trying to know which part of the code (in .py or .js or .json) that let the field value to appear after submitting as: EMP/0001: Maher Hamdan (which is the autoname:employee_name)?
Actually it is appearing in this shape only after submitting. But before submitting, it is appearing as autoname only (EMP/0001).
I attached two pictures, one shows the field before click on submit and one shows after clicking on submit.

Before Submitting:

After Submitting:

Appreciate the kindly help because I need to know how this can be made as I need to do this customization in some other forms.

Regards
Bilal

Would this help?

Thank you Umair. I know that the js file is the part that is responsible to set the value of the field For Employee to be: EMP/0001:Maher Hamdan as shown in the previous attached picture.
But the question is which part of this js script that is responsible to set the value in this shape?

Really I have a feeling that the below part is the responsible because it is event that is related to post_render.

But I do not see that it is setting the employee field to have the value of autoname:employee_name even I do not see any part of the script that is putting the ( : ). What I see in this part of the script that it is setting the value to empty as it is appearing in the below part: [quote=“umair, post:2, topic:25374”]
cur_frm.set_value(“employee”, “”);
cur_frm.set_value(“employee_name”, “”)
[/quote]

Appreciate if you can direct me which part of the script that is setting the value to autoname:employee_name with fully thanks.
Regards
Bilal