Per documentation:
The trigger function must be defined before the trigger itself can be
created. The trigger function must be declared as a function taking no
arguments and returning type trigger. (The trigger function receives
its input through a specially-passed TriggerData structure, not in the
form of ordinary function arguments.)
Bold emphasis mine.
To pass those parameters:
arguments
An optional comma-separated list of arguments to be provided to the
function when the trigger is executed. The arguments are literal
string constants. Simple names and numeric constants can be written
here, too, but they will all be converted to strings. Please check the
description of the implementation language of the trigger function to
find out how these arguments can be accessed within the function; it
might be different from normal function arguments.
And finally, in the chapter Trigger Procedures:
Note that the function must be declared with no arguments even if it
expects to receive arguments specified in CREATE TRIGGER — trigger
arguments are passed via TG_ARGV, as described below.
...
TG_ARGV[]
Data type array of text; the arguments from the CREATE TRIGGER statement. The index counts from 0. Invalid indexes (less than 0 or greater than or equal to tg_nargs) result in a null value.
The final difficulty is that SQL only works with static identifiers. If you want to parametrize a column name, you need dynamic SQL. In a plpgsql function, use EXECUTE for that.
Example
CREATE OR REPLACE FUNCTION trg_foo()
RETURNS trigger AS
$func$
DECLARE
_result text;
BEGIN
CASE TG_OP
WHEN 'INSERT', 'UPDATE' THEN
EXECUTE format('SELECT %I FROM %s WHERE tbl_id = $1', TG_ARGV[1]
, TG_ARGV[0]::regclass)
INTO _result
USING NEW.sometbl_id;
WHEN ...
END CASE;
-- do something with _result ...
RETURN NULL; -- since it's an AFTER trigger
END
$func$ LANGUAGE plpgsql;
CREATE TRIGGER foo_trigger
AFTER INSERT OR UPDATE OR DELETE ON foo
FOR EACH ROW
EXECUTE PROCEDURE trg_foo('foo', 'field'); -- two params: table, field
Answer on SO with details about the cast to regclass:
Table name as a PostgreSQL function parameter
