SELECT * ,
CASE t2.field_max_occupancy_value
WHEN  'one' THEN 1
WHEN  'two' THEN 2
WHEN  'three' THEN 3
WHEN  'four' THEN 4
WHEN  'five' THEN 5
WHEN  'six' THEN 6
WHEN  'seven' THEN 7
WHEN  'eight' THEN 8
WHEN  'nine' THEN 9
WHEN  'ten' THEN 10
ELSE 0
END AS numfield
FROM field_data_field_rate_dates t1
LEFT JOIN field_data_maximum_occupancy t2 on t2.entity_id = t1.entity_id
WHERE t1.field_rate_dates_value <=  '2015-07-11'

SELECT a.* FROM
(
SELECT * ,
CASE t2.field_max_occupancy_value
WHEN  'one' THEN 1
WHEN  'two' THEN 2
WHEN  'three' THEN 3
WHEN  'four' THEN 4
WHEN  'five' THEN 5
WHEN  'six' THEN 6
WHEN  'seven' THEN 7
WHEN  'eight' THEN 8
WHEN  'nine' THEN 9
WHEN  'ten' THEN 10
ELSE 0
END AS numfield
FROM field_data_field_rate_dates t1
LEFT JOIN field_data_maximum_occupancy t2 on t2.entity_id = t1.entity_id
WHERE t1.field_rate_dates_value <=  '2015-07-11'
)a
WHERE  numfield >= 3

SELECT
    *,
    CASE t2.field_max_occupancy_value
        WHEN  'one' THEN 1
        WHEN  'two' THEN 2
        WHEN  'three' THEN 3
        WHEN  'four' THEN 4
        WHEN  'five' THEN 5
        WHEN  'six' THEN 6
        WHEN  'seven' THEN 7
        WHEN  'eight' THEN 8
        WHEN  'nine' THEN 9
        WHEN  'ten' THEN 10
    ELSE 0
        END AS numfield
FROM field_data_field_rate_dates t1
LEFT JOIN field_data_maximum_occupancy t2 on t2.entity_id = t1.entity_id
WHERE t1.field_rate_dates_value <=  '2015-07-11' &&
    (CASE t2.field_max_occupancy_value
        WHEN  'one' THEN 1
        WHEN  'two' THEN 2
        WHEN  'three' THEN 3
        WHEN  'four' THEN 4
        WHEN  'five' THEN 5
        WHEN  'six' THEN 6
        WHEN  'seven' THEN 7
        WHEN  'eight' THEN 8
        WHEN  'nine' THEN 9
        WHEN  'ten' THEN 10
        ELSE 0
        END) >=3;