Custom select with database data

Hi there.

I've a problem...

i got a select custom filter and i need to load data into select from my database (mysql) . any help??
i'm trying to assign the variable with the string of the parameters to the "values" variable but this is the result :

example :

with php script i get the string with the parameters from my database (ex : myvar=['hello' , 'world'])
then i assign it to values (values:var) and in the select i got this :
SELECT
[
'
h
e
l
l
o
'
,
'
w
o
r
l
d
'
] exactly charater by charater.
help please