sugarcrm filter on relative field

You can extend the vardef file to add a "filter_definition". For example, in the field custom/Extension/modules/<module>/Ext/Vardefs/sugarfield_<field_name>.php, you can add something like:

$dictionary['<module>']['fields']['<field_name>']['filter_definition'] = [
    [
        'aclroles.name' => '<role_name>'
    ]
];

Then do a quick repair and rebuild - and by default, it will auto-filter based on the definition above - but this doesn't enforce the filter, users are free to remove the filter and set any record they want, but the default search will filter by the role you specify.

Well, I guess you can do an onlyread field, as same as you do with the relationship of the role field you can do with readonly.
If I am sure you must do 

$dictionary['<module>']['fields']['<field_name>']['filter_definition']['readonly'] = true;

And that converts the field in a simply label, not editable by the user.

Well, I guess you can do an onlyread field, as same as you do with the relationship of the role field you can do with readonly.
If I am sure you must do 

$dictionary['<module>']['fields']['<field_name>']['filter_definition']['readonly'] = true;

And that converts the field in a simply label, not editable by the user.