[v1: drop る] + させられる [v5: う-row → あ-row] + せられる [v5: う-row → あ-row] + される (not after す) [する → させられる] [来る → 来させられる]
The causative-passive says the subject was made to do something, usually against their will. A る-verb drops る and adds させられる; a う-verb moves its last sound to the あ-row and adds せられる. する becomes させられる and くる来る becomes きさせられる来させられる (こさせられる).
The person who did the forcing takes に, the one who had to do it is the subject, and the object keeps を.
A う-verb has a shorter form: the あ-row plus される. In speech it is more common than the long form.
Verbs ending in す and all る-verbs have no short form.
The plain passive says something was done to you. The causative-passive says you were made to do it yourself.
With a verb of thinking or feeling, the causative-passive says something moved you, with no sense of being forced. The cause takes に, usually には.