Oracle BI report for account hierarchy

I am trying to create a oracle BI report for account hierarchy, but I'm a bit stuck. I used the code below but get a message of missing right parentheses.

SELECT
LEVEL AS hierarchy_level,
SYS_CONNECT_BY_PATH(ffv.flex_value || ' - ' || ffv.description, ' > ') AS account_hierarchy_path,
ffv.flex_value AS account_segment_value,
ffv.description AS account_segment_description
FROM
GL_SEG_VAL_HIERARCHIES gsvh,
FND_FLEX_VALUES_VL ffv
WHERE
gsvh.flex_value_set_id = (SELECT flex_value_set_id FROM FND_FLEX_VALUE_SETS WHERE flex_value_set_name = :P_FLEX_VALUE_SET_NAME)