I have directory filed which is many2one

Then in search view I have:

<field name="directory" filter_domain="[('directory','child_of',self)]"/>

It works if I search for a string but I cannot select exact match from the dropdown. It shows me options but gives an empty result. If I change to:

<field name="directory"/>

Then I can select exact match from the dropdown but it doesn't show records from children categories (this is the goal)