Using Lateral

In the past I could use this in a query:

SELECT
DISTINCT ut,
CASE
WHEN xpath_exists ('//t:address_spec/t:country/text()',
q.address_spec,
p.ns)
THEN unnest (xpath ('//t:address_spec/t:country/text()',
q.address_spec,
p.ns))::citext
ELSE NULL
END country,

No longer. The error message suggests I should use a lateral query.
But I could not figure out in the documentation how to get the same
result using a "lateral" construct.

Just selecting "unnest(...)" gives the wrong result because if the
xpath does not exist all the other parts of the query (like 'ut' in
this case) also are empty.

Regards
Johann

--
Because experiencing your loyal love is better than life itself,
my lips will praise you. (Psalm 63:3)