+---------+------+
| id_user | name |
+---------+------+
|       1 | A    |
|       2 | B    |
|       3 | C    |
|       4 | D    |
|       5 | E    |
+---------+------+

+-------------+-------------+
| id_follower | id_followed |
+-------------+-------------+
|           1 |           2 |
|           1 |           3 |
|           1 |           5 |
+-------------+-------------+

+---------+--------------+---------------+
| id_post | id_user_post |     post      |
+---------+--------------+---------------+
|       1 |            2 | hi            |
|       2 |            3 | hello         |
|       3 |            5 | hey you       |
|       4 |            4 | come on       |
|       5 |            5 | where are you |
+---------+--------------+---------------+

SELECT u.name AS n
    ,p.post AS t
FROM community AS c
LEFT JOIN users AS u ON u.id_user = c.id_followed
LEFT JOIN posts AS p ON c.id_followed = p.id_user_post
WHERE u.id_follower = 1

SELECT u.name as n, p.post as t
FROM Community c
LEFT JOIN Users u ON c.id_followed = u.id_user
LEFT JOIN Posts p ON c.id_followed = p.id_user_post
WHERE c.id_follower = 1

;WITH USERS AS(
    SELECT *
    FROM (VALUES (1,'A'),
                 (2,'B'),
                 (3,'C'),
                 (4,'D'),
                 (5,'E')) U(id_user, name))
, Community AS(
    SELECT *
    FROM (VALUES (1,2),
                 (1,3),
                 (1,5)) C(id_follower, id_followed))
, posts AS(
    SELECT *
    FROM (VALUES (1,2,'hi'),
                 (2,3,'hello'),
                 (3,5,'hey you'),
                 (4,4,'come on'),
                 (5,5,'where are you')) P(id_post, id_user_post, post))


SELECT u.name as n, p.post as t
FROM Community c
LEFT JOIN Users u ON c.id_followed = u.id_user
LEFT JOIN Posts p ON c.id_followed = p.id_user_post
WHERE c.id_follower = 1